srun (1)

---

NAME

srun - Run parallel jobs

SYNOPSIS

srun [OPTIONS...] executable [args...]

DESCRIPTION

Run a parallel job on cluster managed by SLURM. If necessary, srun will first create a resource allocation in which to run the parallel job.

The following document describes the the influence of various options on the allocation of cpus to jobs and tasks.
http://slurm.schedmd.com/cpu_management.html

OPTIONS

-A, --account=<account>

Charge resources used by this job to specified account. The account is an arbitrary string. The account name may be changed after job submission using the scontrol command.

--acctg-freq

Define the job accounting and profiling sampling intervals. This can be used to override the JobAcctGatherFrequency parameter in SLURM's configuration file, slurm.conf. The supported format is follows:

--acctg-freq=<datatype>=<interval>

where <datatype>=<interval> specifies the task sampling interval for the jobacct_gather plugin or a sampling interval for a profiling type by the acct_gather_profile plugin. Multiple, comma-separated <datatype>=<interval> intervals may be specified. Supported datatypes are as follows:

task=<interval>

where <interval> is the task sampling interval in seconds for the jobacct_gather plugins and for task profiling by the acct_gather_profile plugin.

energy=<interval>

where <interval> is the sampling interval in seconds for energy profiling using the acct_gather_energy plugin

network=<interval>

where <interval> is the sampling interval in seconds for infiniband profiling using the acct_gather_infiniband plugin.

filesystem=<interval>

where <interval> is the sampling interval in seconds for filesystem profiling using the acct_gather_filesystem plugin.

The default value for the task sampling interval is 30. The default value for all other intervals is 0. An interval of 0 disables sampling of the specified type. If the task sampling interval is 0, accounting information is collected only at job termination (reducing SLURM interference with the job).

Smaller (non-zero) values have a greater impact upon job performance, but a value of 30 seconds is not likely to be noticeable for applications having less than 10,000 tasks.

-B --extra-node-info=<sockets[:cores[:threads]]>

Request a specific allocation of resources with details as to the number and type of computational resources within a cluster: number of sockets (or physical processors) per node, cores per socket, and threads per core. The total amount of resources being requested is the product of all of the terms. Each value specified is considered a minimum. An asterisk (*) can be used as a placeholder indicating that all available resources of that type are to be utilized. As with nodes, the individual levels can also be specified in separate options if desired:

    --sockets-per-node=<sockets>
    --cores-per-socket=<cores>
    --threads-per-core=<threads>

If task/affinity plugin is enabled, then specifying an allocation in this manner also sets a default --cpu_bind option of threads if the -B option specifies a thread count, otherwise an option of cores if a core count is specified, otherwise an option of sockets. If SelectType is configured to select/cons_res, it must have a parameter of CR_Core, CR_Core_Memory, CR_Socket, or CR_Socket_Memory for this option to be honored. This option is not supported on BlueGene systems (select/bluegene plugin is configured). If not specified, the scontrol show job will display 'ReqS:C:T=*:*:*'.

--begin=<time>

Defer initiation of this job until the specified time. It accepts times of the form HH:MM:SS to run a job at a specific time of day (seconds are optional). (If that time is already past, the next day is assumed.) You may also specify midnight, noon, or teatime (4pm) and you can have a time-of-day suffixed with AM or PM for running in the morning or the evening. You can also say what day the job will be run, by specifying a date of the form MMDDYY or MM/DD/YY YYYY-MM-DD. Combine date and time using the following format YYYY-MM-DD[THH:MM[:SS]]. You can also give times like now + count time-units, where the time-units can be seconds (default), minutes, hours, days, or weeks and you can tell SLURM to run the job today with the keyword today and to run the job tomorrow with the keyword tomorrow. The value may be changed after job submission using the scontrol command. For example:

   --begin=16:00
   --begin=now+1hour
   --begin=now+60           (seconds by default)
   --begin=2010-01-20T12:34:00

Notes on date/time specifications:
 - Although the 'seconds' field of the HH:MM:SS time specification is allowed by the code, note that the poll time of the SLURM scheduler is not precise enough to guarantee dispatch of the job on the exact second. The job will be eligible to start on the next poll following the specified time. The exact poll interval depends on the SLURM scheduler (e.g., 60 seconds with the default sched/builtin).
 - If no time (HH:MM:SS) is specified, the default is (00:00:00).
 - If a date is specified without a year (e.g., MM/DD) then the current year is assumed, unless the combination of MM/DD and HH:MM:SS has already passed for that year, in which case the next year is used.

--checkpoint=<time>

Specifies the interval between creating checkpoints of the job step. By default, the job step will have no checkpoints created. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds".

--checkpoint-dir=<directory>

Specifies the directory into which the job or job step's checkpoint should be written (used by the checkpoint/blcr and checkpoint/xlch plugins only). The default value is the current working directory. Checkpoint files will be of the form "<job_id>.ckpt" for jobs and "<job_id>.<step_id>.ckpt" for job steps.

--comment=<string>

An arbitrary comment.

-C, --constraint=<list>

Nodes can have features assigned to them by the SLURM administrator. Users can specify which of these features are required by their job using the constraint option. Only nodes having features matching the job constraints will be used to satisfy the request. Multiple constraints may be specified with AND, OR, exclusive OR, resource counts, etc. Supported constraint options include:

Single Name

Only nodes which have the specified feature will be used. For example, --constraint="intel"

Node Count

A request can specify the number of nodes needed with some feature by appending an asterisk and count after the feature name. For example "--nodes=16 --constraint=graphics*4 ..." indicates that the job requires 16 nodes at that at least four of those nodes must have the feature "graphics."

AND

If only nodes with all of specified features will be used. The ampersand is used for an AND operator. For example, --constraint="intel&gpu"

OR

If only nodes with at least one of specified features will be used. The vertical bar is used for an OR operator. For example, --constraint="intel|amd"

Exclusive OR

If only one of a set of possible options should be used for all allocated nodes, then use the OR operator and enclose the options within square brackets. For example: "--constraint=[rack1|rack2|rack3|rack4]" might be used to specify that all nodes must be allocated on a single rack of the cluster, but any of those four racks can be used.

Multiple Counts

Specific counts of multiple resources may be specified by using the AND operator and enclosing the options within square brackets. For example: "--constraint=[rack1*2&rack2*4]" might be used to specify that two nodes must be allocated from nodes with the feature of "rack1" and four nodes must be allocated from nodes with the feature "rack2".

WARNING: When srun is executed from within salloc or sbatch, the constraint value can only contain a single feature name. None of the other operators are currently supported for job steps.

--contiguous

If set, then the allocated nodes must form a contiguous set. Not honored with the topology/tree or topology/3d_torus plugins, both of which can modify the node ordering. Not honored for a job step's allocation.

--cores-per-socket=<cores>

Restrict node selection to nodes with at least the specified number of cores per socket. See additional information under -B option above when task/affinity plugin is enabled.

--cpu_bind=[{quiet,verbose},]type

Bind tasks to CPUs. Used only when the task/affinity or task/cgroup plugin is enabled. The configuration parameter TaskPluginParam may override these options. For example, if TaskPluginParam is configured to bind to cores, your job will not be able to bind tasks to sockets. NOTE: To have SLURM always report on the selected CPU binding for all commands executed in a shell, you can enable verbose mode by setting the SLURM_CPU_BIND environment variable value to "verbose".

The following informational environment variables are set when --cpu_bind is in use:

        SLURM_CPU_BIND_VERBOSE
        SLURM_CPU_BIND_TYPE
        SLURM_CPU_BIND_LIST

See the ENVIRONMENT VARIABLES section for a more detailed description of the individual SLURM_CPU_BIND* variables.

When using --cpus-per-task to run multithreaded tasks, be aware that CPU binding is inherited from the parent of the process. This means that the multithreaded task should either specify or clear the CPU binding itself to avoid having all threads of the multithreaded task use the same mask/CPU as the parent. Alternatively, fat masks (masks which specify more than one allowed CPU) could be used for the tasks in order to provide multiple CPUs for the multithreaded tasks.

By default, a job step has access to every CPU allocated to the job. To ensure that distinct CPUs are allocated to each job step, use the --exclusive option.

If the job step allocation includes an allocation with a number of sockets, cores, or threads equal to the number of tasks to be started then the tasks will by default be bound to the appropriate resources (auto binding). Disable this mode of operation by explicitly setting "--cpu-bind=none".

Note that a job step can be allocated different numbers of CPUs on each node or be allocated CPUs not starting at location zero. Therefore one of the options which automatically generate the task binding is recommended. Explicitly specified masks or bindings are only honored when the job step has been allocated every available CPU on the node.

Binding a task to a NUMA locality domain means to bind the task to the set of CPUs that belong to the NUMA locality domain or "NUMA node". If NUMA locality domain options are used on systems with no NUMA support, then each socket is considered a locality domain.

Supported options include:

q[uiet]

Quietly bind before task runs (default)

v[erbose]

Verbosely report binding before task runs

no[ne]

Do not bind tasks to CPUs (default unless auto binding is applied)

rank

Automatically bind by task rank. Task zero is bound to socket (or core or thread) zero, etc. Not supported unless the entire node is allocated to the job.

map_cpu:<list>

Bind by mapping CPU IDs to tasks as specified where <list> is <cpuid1>,<cpuid2>,...<cpuidN>. CPU IDs are interpreted as decimal values unless they are preceded with '0x' in which case they are interpreted as hexadecimal values. Not supported unless the entire node is allocated to the job. This option is currently only supported by the task/affinity plugin.

mask_cpu:<list>

Bind by setting CPU masks on tasks as specified where <list> is <mask1>,<mask2>,...<maskN>. CPU masks are always interpreted as hexadecimal values but can be preceded with an optional '0x'. Not supported unless the entire node is allocated to the job. This option is currently only supported by the task/affinity plugin.

rank_ldom

Bind to a NUMA locality domain by rank

map_ldom:<list>

Bind by mapping NUMA locality domain IDs to tasks as specified where <list> is <ldom1>,<ldom2>,...<ldomN>. The locality domain IDs are interpreted as decimal values unless they are preceded with '0x' in which case they are interpreted as hexadecimal values. Not supported unless the entire node is allocated to the job.

mask_ldom:<list>

Bind by setting NUMA locality domain masks on tasks as specified where <list> is <mask1>,<mask2>,...<maskN>. NUMA locality domain masks are always interpreted as hexadecimal values but can be preceded with an optional '0x'. Not supported unless the entire node is allocated to the job.

sockets

Automatically generate masks binding tasks to sockets. Only the CPUs on the socket which have been allocated to the job will be used. If the number of tasks differs from the number of allocated sockets this can result in sub-optimal binding.

cores

Automatically generate masks binding tasks to cores. If the number of tasks differs from the number of allocated cores this can result in sub-optimal binding.

threads

Automatically generate masks binding tasks to threads. If the number of tasks differs from the number of allocated threads this can result in sub-optimal binding.

ldoms

Automatically generate masks binding tasks to NUMA locality domains. If the number of tasks differs from the number of allocated locality domains this can result in sub-optimal binding.

help

Show help message for cpu_bind

--cpu-freq =<requested frequency in kilohertz>

Request that the job step initiated by this srun be run at the requested frequency if possible, on the cpus selected for the step on the compute node(s). In addition to specifying a numerical frequency in kilohertz, the request can specify low, medium, or high for the value. "Low" will select the lowest available frequency, "high" will select the highest available frequency, while "medium" attempts to set a frequency in the middle of the available range. If the numeric value specified does not exactly match a legal available frequency, SLURM will attempt to pick a legal frequency close to the request.

The following informational environment variable is set in the job step when --cpu-freq option is requested.

        SLURM_CPU_FREQ_REQ

This environment variable can also be used to supply the value for the cpu frequency request if it is set when the 'srun' command is issued. The --cpu-freq on the command line will override the environment variable value. See the ENVIRONMENT VARIABLES section for a description of the SLURM_CPU_FREQ_REQ variable.

NOTE: This parameter is treated as a request, not a requirement. If the job step's node does not support setting the cpu frequency, or the requested value is outside the bounds of the legal frequencies, an error is logged, but the job step is allowed to continue.

NOTE: Setting the frequency for just the cpus of the job step implies that the tasks are confined to those cpus. If task confinement (i.e., TaskPlugin=task/affinity or TaskPlugin=task/cgroup with the "ConstrainCores" option) is not configured, this parameter is ignored.

-c, --cpus-per-task=<ncpus>

Request that ncpus be allocated per process. This may be useful if the job is multithreaded and requires more than one CPU per task for optimal performance. The default is one CPU per process. If -c is specified without -n, as many tasks will be allocated per node as possible while satisfying the -c restriction. For instance on a cluster with 8 CPUs per node, a job request for 4 nodes and 3 CPUs per task may be allocated 3 or 6 CPUs per node (1 or 2 tasks per node) depending upon resource consumption by other jobs. Such a job may be unable to execute more than a total of 4 tasks. This option may also be useful to spawn tasks without allocating resources to the job step from the job's allocation when running multiple job steps with the --exclusive option.

WARNING: There are configurations and options interpreted differently by job and job step requests which can result in inconsistencies for this option. For example srun -c2 --threads-per-core=1 prog may allocate two cores for the job, but if each of those cores contains two threads, the job allocation will include four CPUs. The job step allocation will then launch two threads per CPU for a total of two tasks.

WARNING: When srun is executed from within salloc or sbatch, there are configurations and options which can result in inconsistent allocations when -c has a value greater than -c on salloc or sbatch.

-d, --dependency=<dependency_list>

Defer the start of this job until the specified dependencies have been satisfied completed. <dependency_list> is of the form <type:job_id[:job_id][,type:job_id[:job_id]]>. Many jobs can share the same dependency and these jobs may even belong to different users. The value may be changed after job submission using the scontrol command.

after:job_id[:jobid...]

This job can begin execution after the specified jobs have begun execution.

afterany:job_id[:jobid...]

This job can begin execution after the specified jobs have terminated.

afternotok:job_id[:jobid...]

This job can begin execution after the specified jobs have terminated in some failed state (non-zero exit code, node failure, timed out, etc).

afterok:job_id[:jobid...]

This job can begin execution after the specified jobs have successfully executed (ran to completion with an exit code of zero).

expand:job_id

Resources allocated to this job should be used to expand the specified job. The job to expand must share the same QOS (Quality of Service) and partition. Gang scheduling of resources in the partition is also not supported.

singleton

This job can begin execution after any previously launched jobs sharing the same job name and user have terminated.

-D, --chdir=<path>

have the remote processes do a chdir to path before beginning execution. The default is to chdir to the current working directory of the srun process.

-e, --error=<mode>

Specify how stderr is to be redirected. By default in interactive mode, srun redirects stderr to the same file as stdout, if one is specified. The --error option is provided to allow stdout and stderr to be redirected to different locations. See IO Redirection below for more options. If the specified file already exists, it will be overwritten.

-E, --preserve-env

Pass the current values of environment variables SLURM_NNODES and SLURM_NTASKS through to the executable, rather than computing them from commandline parameters.

--epilog=<executable>

srun will run executable just after the job step completes. The command line arguments for executable will be the command and arguments of the job step. If executable is "none", then no srun epilog will be run. This parameter overrides the SrunEpilog parameter in slurm.conf. This parameter is completely independent from the Epilog parameter in slurm.conf.

--exclusive

This option has two slightly different meanings for job and job step allocations. When used to initiate a job, the job allocation cannot share nodes with other running jobs. This is the opposite of --share, whichever option is seen last on the command line will win. The default shared/exclusive behavior depends on system configuration and the partition's Shared option takes precedence over the job's option.

This option can also be used when initiating more than one job step within an existing resource allocation, where you want separate processors to be dedicated to each job step. If sufficient processors are not available to initiate the job step, it will be deferred. This can be thought of as providing resource management for the job within it's allocation. Note that all CPUs allocated to a job are available to each job step unless the --exclusive option is used plus task affinity is configured. Since resource management is provided by processor, the --ntasks option must be specified, but the following options should NOT be specified --relative, --distribution=arbitrary. See EXAMPLE below.

--gid=<group>

If srun is run as root, and the --gid option is used, submit the job with group's group access permissions. group may be the group name or the numerical group ID.

--gres=<list>

Specifies a comma delimited list of generic consumable resources. The format of each entry on the list is "name[:count]". The name is that of the consumable resource. The count is the number of those resources with a default value of 1. The specified resources will be allocated to the job on each node. The available generic consumable resources is configurable by the system administrator. A list of available generic consumable resources will be printed and the command will exit if the option argument is "help". Examples of use include "--gres=gpu:2,mic=1" and "--gres=help". NOTE: By default, a job step is allocated all of the generic resources that have allocated to the job. To change the behavior so that each job step is allocated no generic resources, explicitly set the value of --gres to specify zero counts for each generic resource OR set "--gres=none" OR set the SLURM_STEP_GRES environment variable to "none".

-H, --hold

Specify the job is to be submitted in a held state (priority of zero). A held job can now be released using scontrol to reset its priority (e.g. "scontrol release <job_id>").

-h, --help

Display help information and exit.

--hint=<type>

Bind tasks according to application hints

compute_bound

Select settings for compute bound applications: use all cores in each socket, one thread per core

memory_bound

Select settings for memory bound applications: use only one core in each socket, one thread per core

[no]multithread

[don't] use extra threads with in-core multi-threading which can benefit communication intensive applications

help

show this help message

-I, --immediate[=<seconds>]

exit if resources are not available within the time period specified. If no argument is given, resources must be available immediately for the request to succeed. By default, --immediate is off, and the command will block until resources become available. Since this option's argument is optional, for proper parsing the single letter option must be followed immediately with the value and not include a space between them. For example "-I60" and not "-I 60".

-i, --input=<mode>

Specify how stdin is to redirected. By default, srun redirects stdin from the terminal all tasks. See IO Redirection below for more options. For OS X, the poll() function does not support stdin, so input from a terminal is not possible.

-J, --job-name=<jobname>

Specify a name for the job. The specified name will appear along with the job id number when querying running jobs on the system. The default is the supplied executable program's name. NOTE: This information may be written to the slurm_jobacct.log file. This file is space delimited so if a space is used in the jobname name it will cause problems in properly displaying the contents of the slurm_jobacct.log file when the sacct command is used.

--jobid=<jobid>

Initiate a job step under an already allocated job with job id id. Using this option will cause srun to behave exactly as if the SLURM_JOB_ID environment variable was set.

-K, --kill-on-bad-exit[=0|1]

Controls whether or not to terminate a job if any task exits with a non-zero exit code. If this option is not specified, the default action will be based upon the SLURM configuration parameter of KillOnBadExit. If this option is specified, it will take precedence over KillOnBadExit. An option argument of zero will not terminate the job. A non-zero argument or no argument will terminate the job. Note: This option takes precedence over the -W, --wait option to terminate the job immediately if a task exits with a non-zero exit code. Since this option's argument is optional, for proper parsing the single letter option must be followed immediately with the value and not include a space between them. For example "-K1" and not "-K 1".

-k, --no-kill

Do not automatically terminate a job of one of the nodes it has been allocated fails. This option is only recognized on a job allocation, not for the submission of individual job steps. The job will assume all responsibilities for fault-tolerance. Tasks launch using this option will not be considered terminated (e.g. -K, --kill-on-bad-exit and -W, --wait options will have no effect upon the job step). The active job step (MPI job) will likely suffer a fatal error, but subsequent job steps may be run if this option is specified. The default action is to terminate the job upon node failure.

--launch-cmd

Print external launch command instead of running job normally through SLURM. This option is only valid if using something other than the launch/slurm plugin.

--launcher-opts=<options>

Options for the external launcher if using something other than the launch/slurm plugin.

-l, --label

prepend task number to lines of stdout/err. Normally, stdout and stderr from remote tasks is line-buffered directly to the stdout and stderr of srun. The --label option will prepend lines of output with the remote task id.

-L, --licenses=<license>

Specification of licenses (or other resources available on all nodes of the cluster) which must be allocated to this job. License names can be followed by a colon and count (the default count is one). Multiple license names should be comma separated (e.g. "--licenses=foo:4,bar").

-m, --distribution=

<block|cyclic|arbitrary|plane=<options>[:block|cyclic]>

Specify alternate distribution methods for remote processes. This option controls the assignment of tasks to the nodes on which resources have been allocated, and the distribution of those resources to tasks for binding (task affinity). The first distribution method (before the ":") controls the distribution of resources across nodes. The optional second distribution method (after the ":") controls the distribution of resources across sockets within a node. Note that with select/cons_res, the number of cpus allocated on each socket and node may be different. Refer to http://slurm.schedmd.com/mc_support.html for more information on resource allocation, assignment of tasks to nodes, and binding of tasks to CPUs.

First distribution method:

block

The block distribution method will distribute tasks to a node such that consecutive tasks share a node. For example, consider an allocation of three nodes each with two cpus. A four-task block distribution request will distribute those tasks to the nodes with tasks one and two on the first node, task three on the second node, and task four on the third node. Block distribution is the default behavior if the number of tasks exceeds the number of allocated nodes.

cyclic

The cyclic distribution method will distribute tasks to a node such that consecutive tasks are distributed over consecutive nodes (in a round-robin fashion). For example, consider an allocation of three nodes each with two cpus. A four-task cyclic distribution request will distribute those tasks to the nodes with tasks one and four on the first node, task two on the second node, and task three on the third node. Note that when SelectType is select/cons_res, the same number of CPUs may not be allocated on each node. Task distribution will be round-robin among all the nodes with CPUs yet to be assigned to tasks. Cyclic distribution is the default behavior if the number of tasks is no larger than the number of allocated nodes.

plane

The tasks are distributed in blocks of a specified size. The options include a number representing the size of the task block. This is followed by an optional specification of the task distribution scheme within a block of tasks and between the blocks of tasks. The number of tasks distributed to each node is the same as for cyclic distribution, but the taskids assigned to each node depend on the plane size. For more details (including examples and diagrams), please see
http://slurm.schedmd.com/mc_support.html
and
http://slurm.schedmd.com/dist_plane.html

arbitrary

The arbitrary method of distribution will allocate processes in-order as listed in file designated by the environment variable SLURM_HOSTFILE. If this variable is listed it will over ride any other method specified. If not set the method will default to block. Inside the hostfile must contain at minimum the number of hosts requested and be one per line or comma separated. If specifying a task count (-n, --ntasks=<number>), your tasks will be laid out on the nodes in the order of the file.
NOTE: The arbitrary distribution option on a job allocation only controls the nodes to be allocated to the job and not the allocation of CPUs on those nodes. This option is meant primarily to control a job step's task layout in an existing job allocation for the srun command.

Second distribution method:

block

The block distribution method will distribute tasks to sockets such that consecutive tasks share a socket.

cyclic

The cyclic distribution method will distribute tasks to sockets such that consecutive tasks are distributed over consecutive sockets (in a round-robin fashion).

--mail-type=<type>

Notify user by email when certain event types occur. Valid type values are BEGIN, END, FAIL, REQUEUE, and ALL (any state change). The user to be notified is indicated with --mail-user.

--mail-user=<user>

User to receive email notification of state changes as defined by --mail-type. The default value is the submitting user.

--mem=<MB>

Specify the real memory required per node in MegaBytes. Default value is DefMemPerNode and the maximum value is MaxMemPerNode. If configured, both of parameters can be seen using the scontrol show config command. This parameter would generally be used if whole nodes are allocated to jobs (SelectType=select/linear). Also see --mem-per-cpu. --mem and --mem-per-cpu are mutually exclusive. NOTE: Enforcement of memory limits currently relies upon the task/cgroup plugin or enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected). In both cases memory use is based upon the job's Resident Set Size (RSS). A task may exceed the memory limit until the next periodic accounting sample.

--mem-per-cpu=<MB>

Minimum memory required per allocated CPU in MegaBytes. Default value is DefMemPerCPU and the maximum value is MaxMemPerCPU (see exception below). If configured, both of parameters can be seen using the scontrol show config command. Note that if the job's --mem-per-cpu value exceeds the configured MaxMemPerCPU, then the user's limit will be treated as a memory limit per task; --mem-per-cpu will be reduced to a value no larger than MaxMemPerCPU; --cpus-per-task will be set and value of --cpus-per-task multiplied by the new --mem-per-cpu value will equal the original --mem-per-cpu value specified by the user. This parameter would generally be used if individual processors are allocated to jobs (SelectType=select/cons_res). Also see --mem. --mem and --mem-per-cpu are mutually exclusive.

--mem_bind=[{quiet,verbose},]type

Bind tasks to memory. Used only when the task/affinity plugin is enabled and the NUMA memory functions are available. Note that the resolution of CPU and memory binding may differ on some architectures. For example, CPU binding may be performed at the level of the cores within a processor while memory binding will be performed at the level of nodes, where the definition of "nodes" may differ from system to system. The use of any type other than "none" or "local" is not recommended. If you want greater control, try running a simple test code with the options "--cpu_bind=verbose,none --mem_bind=verbose,none" to determine the specific configuration.

NOTE: To have SLURM always report on the selected memory binding for all commands executed in a shell, you can enable verbose mode by setting the SLURM_MEM_BIND environment variable value to "verbose".

The following informational environment variables are set when --mem_bind is in use:

        SLURM_MEM_BIND_VERBOSE
        SLURM_MEM_BIND_TYPE
        SLURM_MEM_BIND_LIST

See the ENVIRONMENT VARIABLES section for a more detailed description of the individual SLURM_MEM_BIND* variables.

Supported options include:

q[uiet]

quietly bind before task runs (default)

v[erbose]

verbosely report binding before task runs

no[ne]

don't bind tasks to memory (default)

rank

bind by task rank (not recommended)

local

Use memory local to the processor in use

map_mem:<list>

bind by mapping a node's memory to tasks as specified where <list> is <cpuid1>,<cpuid2>,...<cpuidN>. CPU IDs are interpreted as decimal values unless they are preceded with '0x' in which case they interpreted as hexadecimal values (not recommended)

mask_mem:<list>

bind by setting memory masks on tasks as specified where <list> is <mask1>,<mask2>,...<maskN>. memory masks are always interpreted as hexadecimal values. Note that masks must be preceded with a '0x' if they don't begin with [0-9] so they are seen as numerical values by srun.

help

show this help message

--mincpus=<n>

Specify a minimum number of logical cpus/processors per node.

--msg-timeout=<seconds>

Modify the job launch message timeout. The default value is MessageTimeout in the SLURM configuration file slurm.conf. Changes to this are typically not recommended, but could be useful to diagnose problems.

--mpi=<mpi_type>

Identify the type of MPI to be used. May result in unique initiation procedures.

list

Lists available mpi types to choose from.

lam

Initiates one 'lamd' process per node and establishes necessary environment variables for LAM/MPI.

mpich1_shmem

Initiates one process per node and establishes necessary environment variables for mpich1 shared memory model. This also works for mvapich built for shared memory.

mpichgm

For use with Myrinet.

mvapich

For use with Infiniband.

openmpi

For use with OpenMPI.

none

No special MPI processing. This is the default and works with many other versions of MPI.

--multi-prog

Run a job with different programs and different arguments for each task. In this case, the executable program specified is actually a configuration file specifying the executable and arguments for each task. See MULTIPLE PROGRAM CONFIGURATION below for details on the configuration file contents.

-N, --nodes=<minnodes[-maxnodes]>

Request that a minimum of minnodes nodes be allocated to this job. A maximum node count may also be specified with maxnodes. If only one number is specified, this is used as both the minimum and maximum node count. The partition's node limits supersede those of the job. If a job's node limits are outside of the range permitted for its associated partition, the job will be left in a PENDING state. This permits possible execution at a later time, when the partition limit is changed. If a job node limit exceeds the number of nodes configured in the partition, the job will be rejected. Note that the environment variable SLURM_JOB_NUM_NODES (and SLURM_NNODES for backwards compatibility) will be set to the count of nodes actually allocated to the job. See the ENVIRONMENT VARIABLES section for more information. If -N is not specified, the default behavior is to allocate enough nodes to satisfy the requirements of the -n and -c options. The job will be allocated as many nodes as possible within the range specified and without delaying the initiation of the job. The node count specification may include a numeric value followed by a suffix of "k" (multiplies numeric value by 1,024) or "m" (multiplies numeric value by 1,048,576).

-n, --ntasks=<number>

Specify the number of tasks to run. Request that srun allocate resources for ntasks tasks. The default is one task per node, but note that the --cpus-per-task option will change this default.

--network=<type>

Specify the communication protocol to be used. The interpretation of type is system dependent. This option is current supported on systems with IBM's Parallel Environment (PE). See IBM's LoadLeveler job command keyword documentation about the keyword "network" for more information. Multiple values may be specified in a comma separated list. All options are case in-sensitive. Supported values include:

BULK_XFER[=<resources>]

Enable bulk transfer of data using Remote Direct-Memory Access (RDMA). The optional resources specification is a numeric value which can have a suffix of "k", "K", "m", "M", "g" or "G" for kilobytes, megabytes or gigabytes. NOTE: The resources specification is not supported by the underlying IBM infrastructure as of Parallel Environment version 2.2 and no value should be specified at this time. The devices allocated to a job must all be of the same type. The default value depends upon depends upon what hardware is available and in order of preferences is IPONLY (which is not considered in User Space mode), HFI, IB, HPCE, and KMUX.

CAU=<count>

Number of Collecitve Acceleration Units (CAU) required. Applies only to IBM Power7-IH processors. Default value is zero. Independent CAU will be allocated for each programming interface (MPI, LAPI, etc.)

DEVNAME=<name>

Specify the device name to use for communications (e.g. "eth0" or "mlx4_0").

DEVTYPE=<type>

Specify the device type to use for communications. The supported values of type are: "IB" (InfiniBand), "HFI" (P7 Host Fabric Interface), "IPONLY" (IP-Only interfaces), "HPCE" (HPC Ethernet), and "KMUX" (Kernel Emulation of HPCE). The devices allocated to a job must all be of the same type. The default value depends upon depends upon what hardware is available and in order of preferences is IPONLY (which is not considered in User Space mode), HFI, IB, HPCE, and KMUX.

IMMED =<count>

Number of immediate send slots per window required. Applies only to IBM Power7-IH processors. Default value is zero.

INSTANCES =<count>

Specify number of network connections for each task on each network connection. The default instance count is 1.

IPV4

Use Internet Protocol (IP) version 4 communications (default).

IPV6

Use Internet Protocol (IP) version 6 communications.

LAPI

Use the LAPI programming interface.

MPI

Use the MPI programming interface. MPI is the default interface.

PAMI

Use the PAMI programming interface.

SHMEM

Use the OpenSHMEM programming interface.

SN_ALL

Use all available switch networks (default).

SN_SINGLE

Use one available switch network.

UPC

Use the UPC programming interface.

US

Use User Space communications.

Some examples of network specifications:

Instances=2,US,MPI,SN_ALL

Create two user space connections for MPI communications on every switch network for each task.

US,MPI,Instances=3,Devtype=IB

Create three user space connections for MPI communications on every InfiniBand network for each task.

IPV4,LAPI,SN_Single

Create a IP version 4 connection for LAPI communications on one switch network for each task.

Instances=2,US,LAPI,MPI

Create two user space connections each for LAPI and MPI communications on every switch network for each task. Note that SN_ALL is the default option so every switch network is used. Also note that Instances=2 specifies that two connections are established for each protocol (LAPI and MPI) and each task. If there are two networks and four tasks on the node then a total of 32 connections are established (2 instances x 2 protocols x 2 networks x 4 tasks).

--nice[=adjustment]

Run the job with an adjusted scheduling priority within SLURM. With no adjustment value the scheduling priority is decreased by 100. The adjustment range is from -10000 (highest priority) to 10000 (lowest priority). Only privileged users can specify a negative adjustment. NOTE: This option is presently ignored if SchedulerType=sched/wiki or SchedulerType=sched/wiki2.

--ntasks-per-core=<ntasks>

Request the maximum ntasks be invoked on each core. Meant to be used with the --ntasks option. Related to --ntasks-per-node except at the core level instead of the node level. Masks will automatically be generated to bind the tasks to specific core unless --cpu_bind=none is specified. NOTE: This option is not supported unless SelectTypeParameters=CR_Core or SelectTypeParameters=CR_Core_Memory is configured.

--ntasks-per-node=<ntasks>

Request the maximum ntasks be invoked on each node. Meant to be used with the --nodes option. This is related to --cpus-per-task=ncpus, but does not require knowledge of the actual number of cpus on each node. In some cases, it is more convenient to be able to request that no more than a specific number of tasks be invoked on each node. Examples of this include submitting a hybrid MPI/OpenMP app where only one MPI "task/rank" should be assigned to each node while allowing the OpenMP portion to utilize all of the parallelism present in the node, or submitting a single setup/cleanup/monitoring job to each node of a pre-existing allocation as one step in a larger job script.

--ntasks-per-socket=<ntasks>

Request the maximum ntasks be invoked on each socket. Meant to be used with the --ntasks option. Related to --ntasks-per-node except at the socket level instead of the node level. Masks will automatically be generated to bind the tasks to specific sockets unless --cpu_bind=none is specified. NOTE: This option is not supported unless SelectTypeParameters=CR_Socket or SelectTypeParameters=CR_Socket_Memory is configured.

-O, --overcommit

Overcommit resources. Normally, srun will not allocate more than one process per CPU. By specifying --overcommit you are explicitly allowing more than one process per CPU. However no more than MAX_TASKS_PER_NODE tasks are permitted to execute per node. NOTE: MAX_TASKS_PER_NODE is defined in the file slurm.h and is not a variable, it is set at SLURM build time.

-o, --output=<mode>

Specify the mode for stdout redirection. By default in interactive mode, srun collects stdout from all tasks and line buffers this output to the attached terminal. With --output stdout may be redirected to a file, to one file per task, or to /dev/null. See section IO Redirection below for the various forms of mode. If the specified file already exists, it will be overwritten.

If --error is not also specified on the command line, both stdout and stderr will directed to the file specified by --output.

--open-mode=<append|truncate>

Open the output and error files using append or truncate mode as specified. The default value is specified by the system configuration parameter JobFileAppend.

-p, --partition=<partition_names>

Request a specific partition for the resource allocation. If not specified, the default behavior is to allow the slurm controller to select the default partition as designated by the system administrator. If the job can use more than one partition, specify their names in a comma separate list and the one offering earliest initiation will be used.

--profile=<all|none|[energy[,|task[,|lustre[,|network]]]]>

enables detailed data collection by the acct_gather_profile plugin. Detailed data are typically time-series that are stored in an HDF5 file for the job.

All

All data types are collected. (Cannot be combined with other values.)

None

No data types are collected. This is the default.
 (Cannot be combined with other values.)

Energy

Energy data is collected.

Task

Task (I/O, Memory, ...) data is collected.

Lustre

Lustre data is collected.

Network

Network (InfiniBand) data is collected.

--prolog=<executable>

srun will run executable just before launching the job step. The command line arguments for executable will be the command and arguments of the job step. If executable is "none", then no srun prolog will be run. This parameter overrides the SrunProlog parameter in slurm.conf. This parameter is completely independent from the Prolog parameter in slurm.conf.

--propagate[=rlimits]

Allows users to specify which of the modifiable (soft) resource limits to propagate to the compute nodes and apply to their jobs. If rlimits is not specified, then all resource limits will be propagated. The following rlimit names are supported by Slurm (although some options may not be supported on some systems):

ALL

All limits listed below

AS

The maximum address space for a process

CORE

The maximum size of core file

CPU

The maximum amount of CPU time

DATA

The maximum size of a process's data segment

FSIZE

The maximum size of files created. Note that if the user sets FSIZE to less than the current size of the slurmd.log, job launches will fail with a 'File size limit exceeded' error.

MEMLOCK

The maximum size that may be locked into memory

NOFILE

The maximum number of open files

NPROC

The maximum number of processes available

RSS

The maximum resident set size

STACK

The maximum stack size

--pty

Execute task zero in pseudo terminal mode. Implicitly sets --unbuffered. Implicitly sets --error and --output to /dev/null for all tasks except task zero, which may cause those tasks to exit immediately (e.g. shells will typically exit immediately in that situation). Not currently supported on AIX platforms.

-Q, --quiet

Suppress informational messages from srun. Errors will still be displayed.

-q, --quit-on-interrupt

Quit immediately on single SIGINT (Ctrl-C). Use of this option disables the status feature normally available when srun receives a single Ctrl-C and causes srun to instead immediately terminate the running job.

--qos=<qos>

Request a quality of service for the job. QOS values can be defined for each user/cluster/account association in the SLURM database. Users will be limited to their association's defined set of qos's when the SLURM configuration parameter, AccountingStorageEnforce, includes "qos" in it's definition.

-r, --relative=<n>

Run a job step relative to node n of the current allocation. This option may be used to spread several job steps out among the nodes of the current job. If -r is used, the current job step will begin at node n of the allocated nodelist, where the first node is considered node 0. The -r option is not permitted with -w or -x option and will result in a fatal error when not running within a prior allocation (i.e. when SLURM_JOB_ID is not set). The default for n is 0. If the value of --nodes exceeds the number of nodes identified with the --relative option, a warning message will be printed and the --relative option will take precedence.

--resv-ports

Reserve communication ports for this job. Used for OpenMPI.

--reservation=<name>

Allocate resources for the job from the named reservation.

--restart-dir=<directory>

Specifies the directory from which the job or job step's checkpoint should be read (used by the checkpoint/blcrm and checkpoint/xlch plugins only).

-s, --share

The job allocation can share nodes with other running jobs. This is the opposite of --exclusive, whichever option is seen last on the command line will be used. The default shared/exclusive behavior depends on system configuration and the partition's Shared option takes precedence over the job's option. This option may result the allocation being granted sooner than if the --share option was not set and allow higher system utilization, but application performance will likely suffer due to competition for resources within a node.

--signal=<sig_num>[@<sig_time>]

When a job is within sig_time seconds of its end time, send it the signal sig_num. Due to the resolution of event handling by SLURM, the signal may be sent up to 60 seconds earlier than specified. sig_num may either be a signal number or name (e.g. "10" or "USR1"). sig_time must have integer value between zero and 65535. By default, no signal is sent before the job's end time. If a sig_num is specified without any sig_time, the default time will be 60 seconds.

--slurmd-debug=<level>

Specify a debug level for slurmd(8). level may be an integer value between 0 [quiet, only errors are displayed] and 4 [verbose operation]. The slurmd debug information is copied onto the stderr of the job. By default only errors are displayed.

--sockets-per-node=<sockets>

Restrict node selection to nodes with at least the specified number of sockets. See additional information under -B option above when task/affinity plugin is enabled.

--switches=<count>[@<max-time>]

When a tree topology is used, this defines the maximum count of switches desired for the job allocation and optionally the maximum time to wait for that number of switches. If SLURM finds an allocation containing more switches than the count specified, the job remains pending until it either finds an allocation with desired switch count or the time limit expires. It there is no switch count limit, there is no delay in starting the job. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds". The job's maximum time delay may be limited by the system administrator using the SchedulerParameters configuration parameter with the max_switch_wait parameter option. The default max-time is the max_switch_wait SchedulerParameter.

-T, --threads=<nthreads>

Allows limiting the number of concurrent threads used to send the job request from the srun process to the slurmd processes on the allocated nodes. Default is to use one thread per allocated node up to a maximum of 60 concurrent threads. Specifying this option limits the number of concurrent threads to nthreads (less than or equal to 60). This should only be used to set a low thread count for testing on very small memory computers.

-t, --time=<time>

Set a limit on the total run time of the job or job step. If the requested time limit for a job exceeds the partition's time limit, the job will be left in a PENDING state (possibly indefinitely). If the requested time limit for a job step exceeds the partition's time limit, the job step will not be initiated. The default time limit is the partition's default time limit. When the time limit is reached, each task in each job step is sent SIGTERM followed by SIGKILL. The limit is for the job, all job steps are signaled. If the time limit is for a single job step within an existing job allocation, only that job step will be affected. A job time limit supersedes all job step time limits. The interval between SIGTERM and SIGKILL is specified by the SLURM configuration parameter KillWait. A time limit of zero requests that no time limit be imposed. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds".

--task-epilog=<executable>

The slurmstepd daemon will run executable just after each task terminates. This will be executed before any TaskEpilog parameter in slurm.conf is executed. This is meant to be a very short-lived program. If it fails to terminate within a few seconds, it will be killed along with any descendant processes.

--task-prolog=<executable>

The slurmstepd daemon will run executable just before launching each task. This will be executed after any TaskProlog parameter in slurm.conf is executed. Besides the normal environment variables, this has SLURM_TASK_PID available to identify the process ID of the task being started. Standard output from this program of the form "export NAME=value" will be used to set environment variables for the task being spawned.

--test-only

Returns an estimate of when a job would be scheduled to run given the current job queue and all the other srun arguments specifying the job. This limits srun's behavior to just return information; no job is actually submitted. EXCEPTION: On Bluegene/Q systems on when running within an existing job allocation, this disables the use of "runjob" to launch tasks. The program will be executed directly by the slurmd dameon.

--threads-per-core=<threads>

Restrict node selection to nodes with at least the specified number of threads per core. NOTE: "Threads" refers to the number of processing units on each core rather than the number of application tasks to be launched per core. See additional information under -B option above when task/affinity plugin is enabled.

--time-min=<time>

Set a minimum time limit on the job allocation. If specified, the job may have it's --time limit lowered to a value no lower than --time-min if doing so permits the job to begin execution earlier than otherwise possible. The job's time limit will not be changed after the job is allocated resources. This is performed by a backfill scheduling algorithm to allocate resources otherwise reserved for higher priority jobs. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds".

--tmp=<MB>

Specify a minimum amount of temporary disk space.

-u, --unbuffered

Do not line buffer stdout from remote tasks. This option cannot be used with --label.

--usage

Display brief help message and exit.

--uid=<user>

Attempt to submit and/or run a job as user instead of the invoking user id. The invoking user's credentials will be used to check access permissions for the target partition. User root may use this option to run jobs as a normal user in a RootOnly partition for example. If run as root, srun will drop its permissions to the uid specified after node allocation is successful. user may be the user name or numerical user ID.

-V, --version

Display version information and exit.

-v, --verbose

Increase the verbosity of srun's informational messages. Multiple -v's will further increase srun's verbosity. By default only errors will be displayed.

-W, --wait=<seconds>

Specify how long to wait after the first task terminates before terminating all remaining tasks. A value of 0 indicates an unlimited wait (a warning will be issued after 60 seconds). The default value is set by the WaitTime parameter in the slurm configuration file (see slurm.conf(5)). This option can be useful to insure that a job is terminated in a timely fashion in the event that one or more tasks terminate prematurely. Note: The -K, --kill-on-bad-exit option takes precedence over -W, --wait to terminate the job immediately if a task exits with a non-zero exit code.

-w, --nodelist=<host1,host2,... or filename>

Request a specific list of hosts. The job will contain at least these hosts. The list may be specified as a comma-separated list of hosts, a range of hosts (host[1-5,7,...] for example), or a filename. The host list will be assumed to be a filename if it contains a "/" character. If you specify a max node count (-N1-2) if there are more than 2 hosts in the file only the first 2 nodes will be used in the request list. Rather than repeating a host name multiple times, an asterisk and a repitition count may be appended to a host name. For example "host1,host1" and "host1*2" are equivalent.

--wckey=<wckey>

Specify wckey to be used with job. If TrackWCKey=no (default) in the slurm.conf this value is ignored.

-X, --disable-status

Disable the display of task status when srun receives a single SIGINT (Ctrl-C). Instead immediately forward the SIGINT to the running job. Without this option a second Ctrl-C in one second is required to forcibly terminate the job and srun will immediately exit. May also be set via the environment variable SLURM_DISABLE_STATUS.

-x, --exclude=<host1,host2,... or filename>

Request that a specific list of hosts not be included in the resources allocated to this job. The host list will be assumed to be a filename if it contains a "/"character.

-Z, --no-allocate

Run the specified tasks on a set of nodes without creating a SLURM "job" in the SLURM queue structure, bypassing the normal resource allocation step. The list of nodes must be specified with the -w, --nodelist option. This is a privileged option only available for the users "SlurmUser" and "root".

The following options support Blue Gene systems, but may be applicable to other systems as well.

--blrts-image=<path>

Path to blrts image for bluegene block. BGL only. Default from blugene.conf if not set.

--cnload-image=<path>

Path to compute node image for bluegene block. BGP only. Default from blugene.conf if not set.

--conn-type=<type>

Require the block connection type to be of a certain type. On Blue Gene the acceptable of type are MESH, TORUS and NAV. If NAV, or if not set, then SLURM will try to fit a what the DefaultConnType is set to in the bluegene.conf if that isn't set the default is TORUS. You should not normally set this option. If running on a BGP system and wanting to run in HTC mode (only for 1 midplane and below). You can use HTC_S for SMP, HTC_D for Dual, HTC_V for virtual node mode, and HTC_L for Linux mode. For systems that allow a different connection type per dimension you can supply a comma separated list of connection types may be specified, one for each dimension (i.e. M,T,T,T will give you a torus connection is all dimensions expect the first).

-g, --geometry=<XxYxZ> | <AxXxYxZ>

Specify the geometry requirements for the job. On BlueGene/L and BlueGene/P systems there are three numbers giving dimensions in the X, Y and Z directions, while on BlueGene/Q systems there are four numbers giving dimensions in the A, X, Y and Z directions and can not be used to allocate sub-blocks. For example "--geometry=1x2x3x4", specifies a block of nodes having 1 x 2 x 3 x 4 = 24 nodes (actually midplanes on BlueGene).

--ioload-image=<path>

Path to io image for bluegene block. BGP only. Default from blugene.conf if not set.

--linux-image=<path>

Path to linux image for bluegene block. BGL only. Default from blugene.conf if not set.

--mloader-image=<path>

Path to mloader image for bluegene block. Default from blugene.conf if not set.

-R, --no-rotate

Disables rotation of the job's requested geometry in order to fit an appropriate block. By default the specified geometry can rotate in three dimensions.

--ramdisk-image=<path>

Path to ramdisk image for bluegene block. BGL only. Default from blugene.conf if not set.

--reboot

Force the allocated nodes to reboot before starting the job.

srun will submit the job request to the slurm job controller, then initiate all processes on the remote nodes. If the request cannot be met immediately, srun will block until the resources are free to run the job. If the -I (--immediate) option is specified srun will terminate if resources are not immediately available.

When initiating remote processes srun will propagate the current working directory, unless --chdir=<path> is specified, in which case path will become the working directory for the remote processes.

The -n, -c, and -N options control how CPUs and nodes will be allocated to the job. When specifying only the number of processes to run with -n, a default of one CPU per process is allocated. By specifying the number of CPUs required per task (-c), more than one CPU may be allocated per process. If the number of nodes is specified with -N, srun will attempt to allocate at least the number of nodes specified.

Combinations of the above three options may be used to change how processes are distributed across nodes and cpus. For instance, by specifying both the number of processes and number of nodes on which to run, the number of processes per node is implied. However, if the number of CPUs per process is more important then number of processes (-n) and the number of CPUs per process (-c) should be specified.

srun will refuse to allocate more than one process per CPU unless --overcommit (-O) is also specified.

srun will attempt to meet the above specifications "at a minimum." That is, if 16 nodes are requested for 32 processes, and some nodes do not have 2 CPUs, the allocation of nodes will be increased in order to meet the demand for CPUs. In other words, a minimum of 16 nodes are being requested. However, if 16 nodes are requested for 15 processes, srun will consider this an error, as 15 processes cannot run across 16 nodes.

IO Redirection

By default, stdout and stderr will be redirected from all tasks to the stdout and stderr of srun, and stdin will be redirected from the standard input of srun to all remote tasks. If stdin is only to be read by a subset of the spawned tasks, specifying a file to read from rather than forwarding stdin from the srun command may be preferable as it avoids moving and storing data that will never be read.

For OS X, the poll() function does not support stdin, so input from a terminal is not possible.

For BGQ srun only supports stdin to 1 task running on the system. By default it is taskid 0 but can be changed with the -i<taskid> as described below, or --launcher-opts="--stdinrank=<taskid>".

This behavior may be changed with the --output, --error, and --input (-o, -e, -i) options. Valid format specifications for these options are

all

stdout stderr is redirected from all tasks to srun. stdin is broadcast to all remote tasks. (This is the default behavior)

none

stdout and stderr is not received from any task. stdin is not sent to any task (stdin is closed).

taskid

stdout and/or stderr are redirected from only the task with relative id equal to taskid, where 0 <= taskid <= ntasks, where ntasks is the total number of tasks in the current job step. stdin is redirected from the stdin of srun to this same task. This file will be written on the node executing the task.

filename

srun will redirect stdout and/or stderr to the named file from all tasks. stdin will be redirected from the named file and broadcast to all tasks in the job. filename refers to a path on the host that runs srun. Depending on the cluster's file system layout, this may result in the output appearing in different places depending on whether the job is run in batch mode.

format string

srun allows for a format string to be used to generate the named IO file described above. The following list of format specifiers may be used in the format string to generate a filename that will be unique to a given jobid, stepid, node, or task. In each case, the appropriate number of files are opened and associated with the corresponding tasks. Note that any format string containing %t, %n, and/or %N will be written on the node executing the task rather than the node where srun executes, these format specifiers are not supported on a BGQ system.

%A

Job array's master job allocation number.

%a

Job array ID (index) number.

%J

jobid.stepid of the running job. (e.g. "128.0")

%j

jobid of the running job.

%s

stepid of the running job.

%N

short hostname. This will create a separate IO file per node.

%n

Node identifier relative to current job (e.g. "0" is the first node of the running job) This will create a separate IO file per node.

%t

task identifier (rank) relative to current job. This will create a separate IO file per task.

%u

User name.

A number placed between the percent character and format specifier may be used to zero-pad the result in the IO filename. This number is ignored if the format specifier corresponds to non-numeric data (%N for example).

Some examples of how the format string may be used for a 4 task job step with a Job ID of 128 and step id of 0 are included below:

job%J.out

job128.0.out

job%4j.out

job0128.out

job%j-%2t.out

job128-00.out, job128-01.out, ...

INPUT ENVIRONMENT VARIABLES

Some srun options may be set via environment variables. These environment variables, along with their corresponding options, are listed below. Note: Command line options will always override these settings.

PMI_FANOUT

This is used exclusively with PMI (MPICH2 and MVAPICH2) and controls the fanout of data communications. The srun command sends messages to application programs (via the PMI library) and those applications may be called upon to forward that data to up to this number of additional tasks. Higher values offload work from the srun command to the applications and likely increase the vulnerability to failures. The default value is 32.

PMI_FANOUT_OFF_HOST

This is used exclusively with PMI (MPICH2 and MVAPICH2) and controls the fanout of data communications. The srun command sends messages to application programs (via the PMI library) and those applications may be called upon to forward that data to additional tasks. By default, srun sends one message per host and one task on that host forwards the data to other tasks on that host up to PMI_FANOUT. If PMI_FANOUT_OFF_HOST is defined, the user task may be required to forward the data to tasks on other hosts. Setting PMI_FANOUT_OFF_HOST may increase performance. Since more work is performed by the PMI library loaded by the user application, failures also can be more common and more difficult to diagnose.

PMI_TIME

This is used exclusively with PMI (MPICH2 and MVAPICH2) and controls how much the communications from the tasks to the srun are spread out in time in order to avoid overwhelming the srun command with work. The default value is 500 (microseconds) per task. On relatively slow processors or systems with very large processor counts (and large PMI data sets), higher values may be required.

SLURM_CONF

The location of the SLURM configuration file.

SLURM_ACCOUNT

Same as -A, --account

SLURM_ACCTG_FREQ

Same as --acctg-freq

SLURM_BLRTS_IMAGE

Same as --blrts-image

SLURM_CHECKPOINT

Same as --checkpoint

SLURM_CHECKPOINT_DIR

Same as --checkpoint-dir

SLURM_CNLOAD_IMAGE

Same as --cnload-image

SLURM_CONN_TYPE

Same as --conn-type

SLURM_CPU_BIND

Same as --cpu_bind

SLURM_CPU_FREQ_REQ

Same as --cpu-freq. Can specify a numerical frequency in kilohertz, or the request can specify low, medium, or high for the value. "Low" will select the lowest available frequency, "high" will select the highest available frequency, while "medium" attempts to set a frequency in the middle of the available range. If the numeric value specified does not exactly match a legal available frequency, SLURM will attempt to pick a legal frequency close to the request.

SLURM_CPUS_PER_TASK

Same as -c, --cpus-per-task

SLURM_DEBUG

Same as -v, --verbose

SLURMD_DEBUG

Same as -d, --slurmd-debug

SLURM_DEPENDENCY

-P, --dependency=<jobid>

SLURM_DISABLE_STATUS

Same as -X, --disable-status

SLURM_DIST_PLANESIZE

Same as -m plane

SLURM_DISTRIBUTION

Same as -m, --distribution

SLURM_EPILOG

Same as --epilog

SLURM_EXCLUSIVE

Same as --exclusive

SLURM_EXIT_ERROR

Specifies the exit code generated when a SLURM error occurs (e.g. invalid options). This can be used by a script to distinguish application exit codes from various SLURM error conditions. Also see SLURM_EXIT_IMMEDIATE.

SLURM_EXIT_IMMEDIATE

Specifies the exit code generated when the --immediate option is used and resources are not currently available. This can be used by a script to distinguish application exit codes from various SLURM error conditions. Also see SLURM_EXIT_ERROR.

SLURM_GEOMETRY

Same as -g, --geometry

SLURM_GRES

Same as --gres. Also see SLURM_STEP_GRES

SLURM_IMMEDIATE

Same as -I, --immediate

SLURM_IOLOAD_IMAGE

Same as --ioload-image

SLURM_JOB_ID (and SLURM_JOBID for backwards compatibility)

Same as --jobid

SLURM_JOB_NAME

Same as -J, --job-name except within an existing allocation, in which case it is ignored to avoid using the batch job's name as the name of each job step.

SLURM_JOB_NUM_NODES (and SLURM_NNODES for backwards compatibility)

Total number of nodes in the job’s resource allocation.

SLURM_KILL_BAD_EXIT

Same as -K, --kill-on-bad-exit

SLURM_LABELIO

Same as -l, --label

SLURM_LINUX_IMAGE

Same as --linux-image

SLURM_MEM_BIND

Same as --mem_bind

SLURM_MEM_PER_CPU

Same as --mem-per-cpu

SLURM_MEM_PER_NODE

Same as --mem

SLURM_MLOADER_IMAGE

Same as --mloader-image

SLURM_MPI_TYPE

Same as --mpi

SLURM_NETWORK

Same as --network

SLURM_NNODES

Same as -N, --nodes

SLURM_NODELIST

Same as -w, --nodelist

SLURM_NO_ROTATE

Same as -R, --no-rotate

SLURM_NTASKS (and SLURM_NPROCS for backwards compatibility)

Same as -n, --ntasks

SLURM_NTASKS_PER_CORE

Same as --ntasks-per-core

SLURM_NTASKS_PER_NODE

Same as --ntasks-per-node

SLURM_NTASKS_PER_SOCKET

Same as --ntasks-per-socket

SLURM_OPEN_MODE

Same as --open-mode

SLURM_OVERCOMMIT

Same as -O, --overcommit

SLURM_PARTITION

Same as -p, --partition

SLURM_PMI_KVS_NO_DUP_KEYS

If set, then PMI key-pairs will contain no duplicate keys. This is the case for MPICH2 and reduces overhead in testing for duplicates for improved performance

SLURM_PROFILE

Same as --profile

SLURM_PROLOG

Same as --prolog

SLURM_QOS

Same as --qos

SLURM_RAMDISK_IMAGE

Same as --ramdisk-image

SLURM_REMOTE_CWD

Same as -D, --chdir=

SLURM_REQ_SWITCH

When a tree topology is used, this defines the maximum count of switches desired for the job allocation and optionally the maximum time to wait for that number of switches. See --switches

SLURM_RESERVATION

Same as --reservation

SLURM_RESTART_DIR

Same as --restart-dir

SLURM_RESV_PORTS

Same as --resv-ports

SLURM_SIGNAL

Same as --signal

SLURM_STDERRMODE

Same as -e, --error

SLURM_STDINMODE

Same as -i, --input

SLURM_SRUN_REDUCE_TASK_EXIT_MSG

if set and non-zero, successive task exit messages with the same exit code will be printed only once.

SLURM_STEP_GRES

Same as --gres (only applies to job steps, not to job allocations). Also see SLURM_GRES

SLURM_STEP_KILLED_MSG_NODE_ID=ID

If set, only the specified node will log when the job or step are killed by a signal.

SLURM_STDOUTMODE

Same as -o, --output

SLURM_TASK_EPILOG

Same as --task-epilog

SLURM_TASK_PROLOG

Same as --task-prolog

SLURM_THREADS

Same as -T, --threads

SLURM_TIMELIMIT

Same as -t, --time

SLURM_UNBUFFEREDIO

Same as -u, --unbuffered

SLURM_WAIT

Same as -W, --wait

SLURM_WAIT4SWITCH

Max time waiting for requested switches. See --switches

SLURM_WCKEY

Same as -W, --wckey

SLURM_WORKING_DIR

-D, --chdir

OUTPUT ENVIRONMENT VARIABLES

srun will set some environment variables in the environment of the executing tasks on the remote compute nodes. These environment variables are:

SLURM_CHECKPOINT_IMAGE_DIR

Directory into which checkpoint images should be written if specified on the execute line.

SLURM_CPU_BIND_VERBOSE

--cpu_bind verbosity (quiet,verbose).

SLURM_CPU_BIND_TYPE

--cpu_bind type (none,rank,map_cpu:,mask_cpu:)

SLURM_CPU_BIND_LIST

--cpu_bind map or mask list (list of SLURM CPU IDs or masks for this node, CPU_ID = Board_ID x threads_per_board + Socket_ID x threads_per_socket + Core_ID x threads_per_core + Thread_ID).

SLURM_CPU_FREQ_REQ

Contains the value requested for cpu frequency on the srun command as a numerical frequency in kilohertz, or a coded value for a request of low, medium, or high for the frequency. See the description of the --cpu-freq option or the SLURM_CPU_FREQ_REQ input environment variable.

SLURM_CPUS_ON_NODE

Count of processors available to the job on this node. Note the select/linear plugin allocates entire nodes to jobs, so the value indicates the total count of CPUs on the node. For the select/cons_res plugin, this number indicates the number of cores on this node allocated to the job.

SLURM_DISTRIBUTION

Distribution type for the allocated jobs. Set the distribution with -m, --distribution.

SLURM_GTIDS

Global task IDs running on this node. Zero origin and comma separated.

SLURM_JOB_CPUS_PER_NODE

Number of CPUS per node.

SLURM_JOB_DEPENDENCY

Set to value of the --dependency option.

SLURM_JOB_ID (and SLURM_JOBID for backwards compatibility)

Job id of the executing job

SLURM_JOB_NAME

Set to the value of the --job-name option or the command name when srun is used to create a new job allocation. Not set when srun is used only to create a job step (i.e. within an existing job allocation).

SLURM_LAUNCH_NODE_IPADDR

IP address of the node from which the task launch was initiated (where the srun command ran from)

SLURM_LOCALID

Node local task ID for the process within a job

SLURM_MEM_BIND_VERBOSE

--mem_bind verbosity (quiet,verbose).

SLURM_MEM_BIND_TYPE

--mem_bind type (none,rank,map_mem:,mask_mem:)

SLURM_MEM_BIND_LIST

--mem_bind map or mask list (<list of IDs or masks for this node>)

SLURM_NNODES

Total number of nodes in the job's resource allocation

SLURM_NODE_ALIASES

Sets of node name, communication address and hostname for nodes allocated to the job from the cloud. Each element in the set if colon separated and each set is comma separated. For example: SLURM_NODE_ALIASES:=:ec0:1.2.3.4:foo,ec1:1.2.3.5:bar

SLURM_NODEID

The relative node ID of the current node

SLURM_NODELIST

List of nodes allocated to the job

SLURM_NTASKS (and SLURM_NPROCS for backwards compatibility)

Total number of processes in the current job

SLURM_PRIO_PROCESS

The scheduling priority (nice value) at the time of job submission. This value is propagated to the spawned processes.

SLURM_PROCID

The MPI rank (or relative process ID) of the current process

SLURM_SRUN_COMM_HOST

IP address of srun communication host.

SLURM_SRUN_COMM_PORT

srun communication port.

SLURM_STEP_LAUNCHER_PORT

Step launcher port.

SLURM_STEP_NODELIST

List of nodes allocated to the step.

SLURM_STEP_NUM_NODES

Number of nodes allocated to the step.

SLURM_STEP_NUM_TASKS

Number of processes in the step.

SLURM_STEP_TASKS_PER_NODE

Number of processes per node within the step.

SLURM_STEP_ID (and SLURM_STEPID for backwards compatibility)

The step ID of the current job

SLURM_SUBMIT_DIR

The directory from which srun was invoked.

SLURM_SUBMIT_HOST

The hostname of the computer from which salloc was invoked.

SLURM_TASK_PID

The process ID of the task being started.

SLURM_TASKS_PER_NODE

Number of tasks to be initiated on each node. Values are comma separated and in the same order as SLURM_NODELIST. If two or more consecutive nodes are to have the same task count, that count is followed by "(x#)" where "#" is the repetition count. For example, "SLURM_TASKS_PER_NODE=2(x3),1" indicates that the first three nodes will each execute three tasks and the fourth node will execute one task.

SLURM_TOPOLOGY_ADDR

This is set only if the system has the topology/tree plugin configured. The value will be set to the names network switches which may be involved in the job's communications from the system's top level switch down to the leaf switch and ending with node name. A period is used to separate each hardware component name.

SLURM_TOPOLOGY_ADDR_PATTERN

This is set only if the system has the topology/tree plugin configured. The value will be set component types listed in SLURM_TOPOLOGY_ADDR. Each component will be identified as either "switch" or "node". A period is used to separate each hardware component type.

SRUN_DEBUG

Set to the logging level of the srun command. Default value is 3 (info level). The value is incremented or decremented based upon the --verbose and --quiet options.

MPIRUN_NOALLOCATE

Do not allocate a block on Blue Gene systems only.

MPIRUN_NOFREE

Do not free a block on Blue Gene systems only.

MPIRUN_PARTITION

The block name on Blue Gene systems only.

SIGNALS AND ESCAPE SEQUENCES

Signals sent to the srun command are automatically forwarded to the tasks it is controlling with a few exceptions. The escape sequence <control-c> will report the state of all tasks associated with the srun command. If <control-c> is entered twice within one second, then the associated SIGINT signal will be sent to all tasks and a termination sequence will be entered sending SIGCONT, SIGTERM, and SIGKILL to all spawned tasks. If a third <control-c> is received, the srun program will be terminated without waiting for remote tasks to exit or their I/O to complete.

The escape sequence <control-z> is presently ignored. Our intent is for this put the srun command into a mode where various special actions may be invoked.

MPI SUPPORT

MPI use depends upon the type of MPI being used. There are three fundamentally different modes of operation used by these various MPI implementation.

1. SLURM directly launches the tasks and performs initialization of communications (Quadrics MPI, MPICH2, MPICH-GM, MVAPICH, MVAPICH2 and some MPICH1 modes). For example: "srun -n16 a.out".

2. SLURM creates a resource allocation for the job and then mpirun launches tasks using SLURM's infrastructure (OpenMPI, LAM/MPI, HP-MPI and some MPICH1 modes).

3. SLURM creates a resource allocation for the job and then mpirun launches tasks using some mechanism other than SLURM, such as SSH or RSH (BlueGene MPI and some MPICH1 modes). These tasks initiated outside of SLURM's monitoring or control. SLURM's epilog should be configured to purge these tasks when the job's allocation is relinquished.

See http://slurm.schedmd.com/mpi_guide.html for more information on use of these various MPI implementation with SLURM.

MULTIPLE PROGRAM CONFIGURATION

Comments in the configuration file must have a "#" in column one. The configuration file contains the following fields separated by white space:

Task rank

One or more task ranks to use this configuration. Multiple values may be comma separated. Ranges may be indicated with two numbers separated with a '-' with the smaller number first (e.g. "0-4" and not "4-0"). To indicate all tasks not otherwise specified, specify a rank of '*' as the last line of the file. If an attempt is made to initiate a task for which no executable program is defined, the following error message will be produced "No executable program specified for this task".

Executable

The name of the program to execute. May be fully qualified pathname if desired.

Arguments

Program arguments. The expression "%t" will be replaced with the task's number. The expression "%o" will be replaced with the task's offset within this range (e.g. a configured task rank value of "1-5" would have offset values of "0-4"). Single quotes may be used to avoid having the enclosed values interpreted. This field is optional. Any arguments for the program entered on the command line will be added to the arguments specified in the configuration file.

For example:

###################################################################
# srun multiple program configuration file
#
# srun -n8 -l --multi-prog silly.conf
###################################################################
4-6       hostname
1,7       echo  task:%t
0,2-3     echo  offset:%o

> srun -n8 -l --multi-prog silly.conf
0: offset:0
1: task:1
2: offset:1
3: offset:2
4: linux15.llnl.gov
5: linux16.llnl.gov
6: linux17.llnl.gov
7: task:7

EXAMPLES

This simple example demonstrates the execution of the command hostname in eight tasks. At least eight processors will be allocated to the job (the same as the task count) on however many nodes are required to satisfy the request. The output of each task will be proceeded with its task number. (The machine "dev" in the example below has a total of two CPUs per node)

> srun -n8 -l hostname
0: dev0
1: dev0
2: dev1
3: dev1
4: dev2
5: dev2
6: dev3
7: dev3

The srun -r option is used within a job script to run two job steps on disjoint nodes in the following example. The script is run using allocate mode instead of as a batch job in this case.

> cat test.sh
#!/bin/sh
echo $SLURM_NODELIST
srun -lN2 -r2 hostname
srun -lN2 hostname

> salloc -N4 test.sh
dev[7-10]
0: dev9
1: dev10
0: dev7
1: dev8

The following script runs two job steps in parallel within an allocated set of nodes.

> cat test.sh
#!/bin/bash
srun -lN2 -n4 -r 2 sleep 60 &
srun -lN2 -r 0 sleep 60 &
sleep 1
squeue
squeue -s
wait

> salloc -N4 test.sh
  JOBID PARTITION     NAME     USER  ST      TIME  NODES NODELIST
  65641     batch  test.sh   grondo   R      0:01      4 dev[7-10]

STEPID     PARTITION     USER      TIME NODELIST
65641.0        batch   grondo      0:01 dev[7-8]
65641.1        batch   grondo      0:01 dev[9-10]

This example demonstrates how one executes a simple MPICH job. We use srun to build a list of machines (nodes) to be used by mpirun in its required format. A sample command line and the script to be executed follow.

> cat test.sh
#!/bin/sh
MACHINEFILE="nodes.$SLURM_JOB_ID"

# Generate Machinefile for mpich such that hosts are in the same
#  order as if run via srun
#
srun -l /bin/hostname | sort -n | awk '{print $2}' > $MACHINEFILE

# Run using generated Machine file:
mpirun -np $SLURM_NTASKS -machinefile $MACHINEFILE mpi-app

rm $MACHINEFILE

> salloc -N2 -n4 test.sh

This simple example demonstrates the execution of different jobs on different nodes in the same srun. You can do this for any number of nodes or any number of jobs. The executables are placed on the nodes sited by the SLURM_NODEID env var. Starting at 0 and going to the number specified on the srun commandline.

> cat test.sh
case $SLURM_NODEID in
    0) echo "I am running on "
       hostname ;;
    1) hostname
       echo "is where I am running" ;;
esac

> srun -N2 test.sh
dev0
is where I am running
I am running on
dev1

This example demonstrates use of multi-core options to control layout of tasks. We request that four sockets per node and two cores per socket be dedicated to the job.

> srun -N2 -B 4-4:2-2 a.out

This example shows a script in which Slurm is used to provide resource management for a job by executing the various job steps as processors become available for their dedicated use.

> cat my.script
#!/bin/bash
srun --exclusive -n4 prog1 &
srun --exclusive -n3 prog2 &
srun --exclusive -n1 prog3 &
srun --exclusive -n1 prog4 &
wait

COPYING

Copyright (C) 2006-2007 The Regents of the University of California. Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
Copyright (C) 2008-2010 Lawrence Livermore National Security.
Copyright (C) 2010-2013 SchedMD LLC.

This file is part of SLURM, a resource management program. For details, see <http://slurm.schedmd.com/>.

SLURM is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

SLURM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

SEE ALSO

salloc(1), sattach(1), sbatch(1), sbcast(1), scancel(1), scontrol(1), squeue(1), slurm.conf(5), sched_setaffinity (2), numa (3) getrlimit (2)

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