    Option(s) define multiple jobs in a co-scheduled heterogeneous job.
    For more details about heterogeneous jobs see the document
    .br
    https://slurm.schedmd.com/heterogeneous_jobs.html

    .SH "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 influence of various options on the
    allocation of cpus to jobs and tasks.
    .br
    https://slurm.schedmd.com/cpu_management.html

    .SH "RETURN VALUE"
    srun will return the highest exit code of all tasks run or the highest signal
    (with the high-order bit set in an 8-bit integer -- e.g. 128 + signal) of any
    task that exited with a signal.
    .br
    The value 253 is reserved for out-of-memory errors.

    .SH "EXECUTABLE PATH RESOLUTION"

    The executable is resolved in the following order:
    .br

    1. If executable starts with ".", then path is constructed as:
    current working directory / executable
    .br
    2. If executable starts with a "/", then path is considered absolute.
    .br
    3. If executable can be resolved through PATH. See \fBpath_resolution\fR(7).
    .br
    4. If executable is in current working directory.
    .br
    .P
    Current working directory is the calling process working directory unless the
    \fB\-\-chdir\fR argument is passed, which will override the current working
    directory.

    .SH "OPTIONS"
    .LP

    .TP
    \fB\-\-accel\-bind\fR=<\fIoptions\fR>
    Control how tasks are bound to generic resources of type gpu, mic and nic.
    Multiple options may be specified. Supported options include:
    .RS
    .TP
    \fBg\fR
    Bind each task to GPUs which are closest to the allocated CPUs.
    \fB\-A\fR, \fB\-\-account\fR=<\fIaccount\fR>
    Charge resources used by this job to specified account.
    The \fIaccount\fR is an arbitrary string. The account name may
    be changed after job submission using the \fBscontrol\fR
    command. This option applies to job allocations.

    .TP
    \fB\-\-acctg\-freq\fR
    Define the job accounting and profiling sampling intervals.
    This can be used to override the \fIJobAcctGatherFrequency\fR parameter in Slurm's
    configuration file, \fIslurm.conf\fR.
    The supported format is follows:
    .RS
    .TP 12
    \fB\-\-acctg\-freq=\fR\fI<datatype>\fR\fB=\fR\fI<interval>\fR
    where \fI<datatype>\fR=\fI<interval>\fR 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 \fI<datatype>\fR=\fI<interval>\fR intervals
    may be specified. Supported datatypes are as follows:
    .RS
    .TP
    \fBtask=\fI<interval>\fR
    where \fI<interval>\fR is the task sampling interval in seconds
    for the jobacct_gather plugins and for task
    profiling by the acct_gather_profile plugin.
    NOTE: This frequency is used to monitor memory usage. If memory limits
    are enforced the highest frequency a user can request is what is configured in
    the slurm.conf file.  They can not turn it off (=0) either.
    .TP
    \fBenergy=\fI<interval>\fR
    where \fI<interval>\fR is the sampling interval in seconds
    for energy profiling using the acct_gather_energy plugin
    .TP
    \fBnetwork=\fI<interval>\fR
    where \fI<interval>\fR is the sampling interval in seconds
    for infiniband profiling using the acct_gather_interconnect
    plugin.
    .TP
    \fBfilesystem=\fI<interval>\fR
    where \fI<interval>\fR is the sampling interval in seconds
    for filesystem profiling using the acct_gather_filesystem
    plugin.
    .TP
    .RE
    .RE
    .br
    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
    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. Values can also be specified as
    min-max. The individual levels can also be specified in separate options if
    desired:
    .nf
        \fB\-\-sockets\-per\-node\fR=<\fIsockets\fR>
        \fB\-\-cores\-per\-socket\fR=<\fIcores\fR>
        \fB\-\-threads\-per\-core\fR=<\fIthreads\fR>
    .fi
    If task/affinity plugin is enabled, then specifying an allocation in this
    manner also sets a default \fB\-\-cpu\-bind\fR option of \fIthreads\fR
    if the \fB\-B\fR option specifies a thread count, otherwise an option of
    \fIcores\fR if a core count is specified, otherwise an option of \fIsockets\fR.
    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.
    If not specified, the scontrol show job will display 'ReqS:C:T=*:*:*'. This
    option applies to job allocations.
    \fBNOTE:\fR This option is mutually exclusive with \fB\-\-hint\fR,
    \fB\-\-threads\-per\-core\fR and \fB\-\-ntasks\-per\-core\fR.

    .TP
    \fB\-\-bb\fR=<\fIspec\fR>
    Burst buffer specification. The form of the specification is system dependent.
    Also see \fB\-\-bbf\fR. This option applies to job allocations.

    .TP
    \fB\-\-bbf\fR=<\fIfile_name\fR>
    Path of file containing burst buffer specification.
    The form of the specification is system dependent.
    Also see \fB\-\-bb\fR. This option applies to job allocations.

    .TP
    \fB\-\-bcast\fR[=<\fIdest_path\fR>]
    Copy executable file to allocated compute nodes.
    If a file name is specified, copy the executable to the specified destination
    file path.
    If the path specified ends with '/' it is treated as a target directory, and
    the destination file name will be slurm_bcast_<job_id>.<step_id>_<nodename>.
    If no dest_path is specified, then the current working directory is used, and
    the filename follows the above pattern.
    For example, "srun \-\-bcast=/tmp/mine \-N3 a.out" will copy the file "a.out"
    from your current directory to the file "/tmp/mine" on each of the three
    allocated compute nodes and execute that file. This option applies to step
    allocations.

    .TP
    \fB\-b\fR, \fB\-\-begin\fR=<\fItime\fR>
    Defer initiation of this job until the specified time.
    It accepts times of the form \fIHH:MM:SS\fR to run a job at
    a specific time of day (seconds are optional).
    \fBscontrol\fR command.
    For example:
    .nf
       \-\-begin=16:00
       \-\-begin=now+1hour
       \-\-begin=now+60           (seconds by default)
       \-\-begin=2010\-01\-20T12:34:00
    .fi

    .RS
    .PP
    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.
    .br
    This option applies to job allocations.
    .RE

    .TP
    \fB\-\-cluster\-constraint\fR=<\fIlist\fR>
    Specifies features that a federated cluster must have to have a sibling job
    submitted to it. Slurm will attempt to submit a sibling job to a cluster if it
    has at least one of the specified features.

    .TP
    \fB\-\-comment\fR=<\fIstring\fR>
    An arbitrary comment. This option applies to job allocations.

    .TP
    \fB\-\-compress\fR[=\fItype\fR]
    Compress file before sending it to compute hosts.
    The optional argument specifies the data compression library to be used.
    Supported values are "lz4" (default) and "zlib".
    Some compression libraries may be unavailable on some systems.
    For use with the \fB\-\-bcast\fR option. This option applies to step
    allocations.

    .TP
    \fB\-C\fR, \fB\-\-constraint\fR=<\fIlist\fR>
    Nodes can have \fBfeatures\fR assigned to them by the Slurm administrator.
    Users can specify which of these \fBfeatures\fR are required by their job
    using the constraint option.
    Only nodes having features matching the job constraints will be used to
    satisfy the request.
    indicates that the job requires 16 nodes and that at least four of those
    nodes must have the feature "graphics."
    .TP
    \fBAND\fR
    If only nodes with all of specified features will be used.
    The ampersand is used for an AND operator.
    For example, \fB\-\-constraint="intel&gpu"\fR
    .TP
    \fBOR\fR
    If only nodes with at least one of specified features will be used.
    The vertical bar is used for an OR operator.
    For example, \fB\-\-constraint="intel|amd"\fR
    .TP
    \fBMatching OR\fR
    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, \fB\-\-constraint="[rack1|rack2|rack3|rack4]"\fR 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.
    .TP
    \fBMultiple Counts\fR
    Specific counts of multiple resources may be specified by using the AND
    operator and enclosing the options within square brackets.
    For example, \fB\-\-constraint="[rack1*2&rack2*4]"\fR 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".

    \fBNOTE:\fR This construct does not support multiple Intel KNL NUMA or MCDRAM
    modes. For example, while \fB\-\-constraint="[(knl&quad)*2&(knl&hemi)*4]"\fR is
    not supported, \fB\-\-constraint="[haswell*2&(knl&hemi)*4]"\fR is supported.
    Specification of multiple KNL modes requires the use of a heterogeneous job.
    .TP
    \fBBrackets\fR
    Brackets can be used to indicate that you are looking for a set of nodes with
    the different requirements contained within the brackets. For example,
    \fB--constraint="[(rack1|rack2)*1&(rack3)*2]"\fR will get you one node with
    either the "rack1" or "rack2" features and two nodes with the "rack3" feature.
    The same request without the brackets will try to find a single node that
    meets those requirements.
    .TP
    \fBParenthesis\fR
    Parenthesis can be used to group like node features together. For example,
    \fB\-\-constraint="[(knl&snc4&flat)*4&haswell*1]"\fR might be used to specify
    that four nodes with the features "knl", "snc4" and "flat" plus one node with
    the feature "haswell" are required. All options within parenthesis should be
    grouped with AND (e.g. "&") operands.
    .RE

    .RS
    \fBWARNING\fR: When srun is executed from within salloc or sbatch,
    the constraint value can only contain a single feature name. None of the
    .TP
    \fB\-\-cores\-per\-socket\fR=<\fIcores\fR>
    Restrict node selection to nodes with at least the specified number of
    cores per socket.  See additional information under \fB\-B\fR option
    above when task/affinity plugin is enabled. This option applies to job
    allocations.

    .TP
    \fB\-\-cpu\-bind\fR=[{\fIquiet,verbose\fR},]\fItype\fR
    Bind tasks to CPUs.
    Used only when the task/affinity or task/cgroup plugin is enabled.
    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 \fB\-\-cpu\-bind\fR
    is in use:
    .nf
    	SLURM_CPU_BIND_VERBOSE
    	SLURM_CPU_BIND_TYPE
    	SLURM_CPU_BIND_LIST
    .fi

    See the \fBENVIRONMENT VARIABLES\fR section for a more detailed description
    of the individual SLURM_CPU_BIND variables. These variable are available
    only if the task/affinity plugin is configured.

    When using \fB\-\-cpus\-per\-task\fR 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.

    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.

    If the -\-cpu\-bind option is not used, the default binding mode will depend
    upon Slurm's configuration and the step's resource allocation.
    If all allocated nodes have the same configured CpuBind mode, that will be used.
    Otherwise if the job's Partition has a configured CpuBind mode, that will be used.
    Otherwise if Slurm has a configured TaskPluginParam value, that mode will be used.
    Otherwise automatic binding will be performed as described below.

    Supported options include:
    .PD 1
    .RS
    .TP
    .B q[uiet]
    Quietly bind before task runs (default)
    .TP
    .B v[erbose]
    Verbosely report binding before task runs
    .TP
    .B no[ne]
    Do not bind tasks to CPUs (default unless auto binding is applied)
    .TP
    .B rank
    Automatically bind by task rank.
    The lowest numbered task on each node is bound to socket (or core or thread) zero, etc.
    Not supported unless the entire node is allocated to the job.
    .TP
    .B map_cpu:<list>
    Bind by setting CPU masks on tasks (or ranks) as specified where <list> is
    setbuf(3). If this option is specified the tasks are executed with
    a pseudo terminal so that the application output is unbuffered. This option
    applies to step allocations.
    .TP
    \fB\-\-usage\fR
    Display brief help message and exit.

    .TP
    \fB\-\-uid\fR=<\fIuser\fR>
    Attempt to submit and/or run a job as \fIuser\fR 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, \fBsrun\fR will drop
    its permissions to the uid specified after node allocation is
    successful. \fIuser\fR may be the user name or numerical user ID. This option
    applies to job and step allocations.

    .TP
    \fB\-\-use-min-nodes\fR
    If a range of node counts is given, prefer the smaller count.

    .TP
    \fB\-V\fR, \fB\-\-version\fR
    Display version information and exit.

    .TP
    \fB\-v\fR, \fB\-\-verbose\fR
    Increase the verbosity of srun's informational messages.  Multiple
    \fB\-v\fR's will further increase srun's verbosity.  By default only
    errors will be displayed. This option applies to job and step allocations.

    .TP
    \fB\-W\fR, \fB\-\-wait\fR=<\fIseconds\fR>
    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
    The host list will be assumed to be a filename if it contains a "/" character.
    If you specify a minimum node or processor count larger than can be satisfied
    by the supplied host list, additional resources will be allocated on other
    nodes as needed.
    Rather than repeating a host name multiple times, an asterisk and
    a repetition count may be appended to a host name. For example
    "host1,host1" and "host1*2" are equivalent. If the number of tasks is given and
    a list of requested nodes is also given, the number of nodes used from that list
    will be reduced to match that of the number of tasks if the number of nodes in
    the list is greater than the number of tasks. This option applies to job and
    step allocations.

    .TP
    \fB\-\-wckey\fR=<\fIwckey\fR>
    Specify wckey to be used with job.  If TrackWCKey=no (default) in the
    slurm.conf this value is ignored. This option applies to job allocations.

    .TP
    \fB\-X\fR, \fB\-\-disable\-status\fR
    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 \fBsrun\fR will immediately exit. May also be
    set via the environment variable SLURM_DISABLE_STATUS. This option applies to
    job allocations.

    .TP
    \fB\-x\fR, \fB\-\-exclude\fR=<\fIhost1,host2,...\fR or \fIfilename\fR>
    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. This option applies to job and step allocations.

    .TP
    \fB\-\-x11\fR[=<\fIall\fR|\fIfirst\fR|\fIlast\fR>]
    Sets up X11 forwarding on all, first or last node(s) of the allocation. This
    option is only enabled if Slurm was compiled with X11 support and
    PrologFlags=x11 is defined in the slurm.conf. Default is \fIall\fR.

    .TP
    \fB\-Z\fR, \fB\-\-no\-allocate\fR
    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
    \fB\-w\fR, \fB\-\-nodelist\fR option.  This is a privileged option
    only available for the users "SlurmUser" and "root". This option applies to job
    allocations.

    .PP
    .B 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,
    .B srun
    is allocated. By specifying the number of CPUs required per task (\fB\-c\fR),
    more than one CPU may be allocated per process. If the number of nodes
    is specified with \fB\-N\fR,
    .B srun
    will attempt to allocate \fIat least\fR the number of nodes specified.
    .PP
    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 (\fB\-n\fR) and the
    number of CPUs per process (\fB\-c\fR) should be specified.
    .PP
    .B srun
    will refuse to  allocate more than one process per CPU unless
    \fB\-\-overcommit\fR (\fB\-O\fR) is also specified.
    .PP
    .B 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 \fIminimum\fR of 16 nodes are being
    requested. However, if 16 nodes are requested for 15 processes,
    .B srun
    will consider this an error, as 15 processes cannot run across 16 nodes.

    .PP
    .B "IO Redirection"
    .PP
    By default, stdout and stderr will be redirected from all tasks to the
    stdout and stderr of \fBsrun\fR, and stdin will be redirected from the
    standard input of \fBsrun\fR 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 \fBsrun\fR command may
    be preferable as it avoids moving and storing data that will never be read.
    .PP
    For OS X, the poll() function does not support stdin, so input from
    a terminal is not possible.
    .PP
    This behavior may be changed with the
    \fB\-\-output\fR, \fB\-\-error\fR, and \fB\-\-input\fR
    (\fB\-o\fR, \fB\-e\fR, \fB\-i\fR) options. Valid format specifications
    for these options are
    .TP 10
    \fBall\fR
    stdout stderr is redirected from all tasks to srun.
    stdin is broadcast to all remote tasks.
    (This is the default behavior)
    .TP
    \fBnone\fR
    stdout and stderr is not received from any task.
    stdin is not sent to any task (stdin is closed).
    this may result in the output appearing in different places depending
    on whether the job is run in batch mode.
    .TP
    \fBfilename pattern\fR
    \fBsrun\fR allows for a filename pattern 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 \fBsrun\fR executes, these format specifiers
    are not supported on a BGQ system.
    .RS 10
    .TP
    \fB\\\\\fR
    Do not process any of the replacement symbols.
    .TP
    \fB%%\fR
    The character "%".
    .TP
    \fB%A\fR
    Job array's master job allocation number.
    .TP
    \fB%a\fR
    Job array ID (index) number.
    .TP
    \fB%J\fR
    jobid.stepid of the running job. (e.g. "128.0")
    .TP
    \fB%j\fR
    jobid of the running job.
    .TP
    \fB%s\fR
    stepid of the running job.
    .TP
    \fB%N\fR
    short hostname. This will create a separate IO file per node.
    .TP
    \fB%n\fR
    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.
    .TP
    \fB%t\fR
    task identifier (rank) relative to current job. This will create a
    separate IO file per task.
    .TP
    \fB%u\fR
    User name.
    .TP
    \fB%x\fR
    .TP
    job%j\-%2t.out
    job128\-00.out, job128\-01.out, ...
    .PP
    .RS -10
    .PP

    .SH "PERFORMANCE"
    .PP
    Executing \fBsrun\fR sends a remote procedure call to \fBslurmctld\fR. If
    enough calls from \fBsrun\fR or other Slurm client commands that send remote
    procedure calls to the \fBslurmctld\fR daemon come in at once, it can result in
    a degradation of performance of the \fBslurmctld\fR daemon, possibly resulting
    in a denial of service.
    .PP
    Do not run \fBsrun\fR or other Slurm client commands that send remote procedure
    calls to \fBslurmctld\fR from loops in shell scripts or other programs. Ensure
    that programs limit calls to \fBsrun\fR to the minimum necessary for the
    information you are trying to gather.

    .SH "INPUT ENVIRONMENT VARIABLES"
    .PP
    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.
    .TP 22
    \fBPMI_FANOUT\fR
    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.
    .TP
    \fBPMI_FANOUT_OFF_HOST\fR
    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 \fBPMI_FANOUT\fR.
    If \fBPMI_FANOUT_OFF_HOST\fR is defined, the user task
    may be required to forward the data to tasks on other hosts.
    Setting \fBPMI_FANOUT_OFF_HOST\fR 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.
    .TP
    .TP
    \fBSLURM_ACCTG_FREQ\fR
    Same as \fB\-\-acctg\-freq\fR
    .TP
    \fBSLURM_BCAST\fR
    Same as \fB\-\-bcast\fR
    .TP
    \fBSLURM_BURST_BUFFER\fR
    Same as \fB\-\-bb\fR
    .TP
    \fBSLURM_CLUSTERS\fR
    Same as \fB-M\fR, \fB\-\-clusters\fR
    .TP
    \fBSLURM_COMPRESS\fR
    Same as \fB\-\-compress\fR
    .TP
    \fBSLURM_CONSTRAINT\fR
    Same as \fB\-C\fR, \fB\-\-constraint\fR
    .TP
    \fBSLURM_CORE_SPEC\fR
    Same as \fB\-\-core\-spec\fR
    .TP
    \fBSLURM_CPU_BIND\fR
    Same as \fB\-\-cpu\-bind\fR
    .TP
    \fBSLURM_CPU_FREQ_REQ\fR
    Same as \fB\-\-cpu\-freq\fR.
    .TP
    \fBSLURM_CPUS_PER_GPU\fR
    Same as \fB\-\-cpus\-per\-gpu\fR
    .TP
    \fBSLURM_CPUS_PER_TASK\fR
    Same as \fB\-c, \-\-cpus\-per\-task\fR
    .TP
    \fBSLURM_DEBUG\fR
    Same as \fB\-v, \-\-verbose\fR
    .TP
    \fBSLURM_DELAY_BOOT\fR
    Same as \fB\-\-delay\-boot\fR
    .TP
    \fBSLURMD_DEBUG\fR
    Same as \fB\-d, \-\-slurmd\-debug\fR
    .TP
    \fBSLURM_DEPENDENCY\fR
    Same as \fB\-P, \-\-dependency\fR=<\fIjobid\fR>
    .TP
    \fBSLURM_DISABLE_STATUS\fR
    Same as \fB\-X, \-\-disable\-status\fR
    .TP
    \fBSLURM_DIST_PLANESIZE\fR
    Plane distribution size. Only used if \fB\-\-distribution=plane\fR,
    without \fI=<size>\fR, is set.
    various Slurm error conditions.
    Also see \fBSLURM_EXIT_IMMEDIATE\fR.
    .TP
    \fBSLURM_EXIT_IMMEDIATE\fR
    Specifies the exit code generated when the \fB\-\-immediate\fR 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 \fBSLURM_EXIT_ERROR\fR.
    .TP
    \fBSLURM_EXPORT_ENV\fR
    Same as \fB\-\-export\fR
    .TP
    \fBSLURM_GPUS\fR
    Same as \fB\-G, \-\-gpus\fR
    .TP
    \fBSLURM_GPU_BIND\fR
    Same as \fB\-\-gpu\-bind\fR
    .TP
    \fBSLURM_GPU_FREQ\fR
    Same as \fB\-\-gpu\-freq\fR
    .TP
    \fBSLURM_GPUS_PER_NODE\fR
    Same as \fB\-\-gpus\-per\-node\fR
    .TP
    \fBSLURM_GPUS_PER_TASK\fR
    Same as \fB\-\-gpus\-per\-task\fR
    .TP
    \fBSLURM_GRES_FLAGS\fR
    Same as \fB\-\-gres\-flags\fR
    .TP
    \fBSLURM_HINT\fR
    Same as \fB\-\-hint\fR
    .TP
    \fBSLURM_GRES\fR
    Same as \fB\-\-gres\fR. Also see \fBSLURM_STEP_GRES\fR
    .TP
    \fBSLURM_IMMEDIATE\fR
    Same as \fB\-I, \-\-immediate\fR
    .TP
    \fBSLURM_JOB_ID\fR
    Same as \fB\-\-jobid\fR
    .TP
    \fBSLURM_JOB_NAME\fR
    Same as \fB\-J, \-\-job\-name\fR 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.
    .TP
    \fBSLURM_JOB_NODELIST\fR
    Same as \fB\-w\fR, \fB\-\-nodelist\fR=<\fIhost1,host2,...\fR or
    \fIfilename\fR>. If job has been resized, ensure that this nodelist is adjusted
    (or undefined) to avoid jobs steps being rejected due to down nodes.
    \fBSLURM_MEM_PER_CPU\fR
    Same as \fB\-\-mem\-per\-cpu\fR
    .TP
    \fBSLURM_MEM_PER_GPU\fR
    Same as \fB\-\-mem\-per\-gpu\fR
    .TP
    \fBSLURM_MEM_PER_NODE\fR
    Same as \fB\-\-mem\fR
    .TP
    \fBSLURM_MPI_TYPE\fR
    Same as \fB\-\-mpi\fR
    .TP
    \fBSLURM_NETWORK\fR
    Same as \fB\-\-network\fR
    .TP
    \fBSLURM_NO_KILL\fR
    Same as \fB\-k\fR, \fB\-\-no\-kill\fR
    .TP
    \fBSLURM_NTASKS\fR (and \fBSLURM_NPROCS\fR for backwards compatibility)
    Same as \fB\-n, \-\-ntasks\fR
    .TP
    \fBSLURM_NTASKS_PER_CORE\fR
    Same as \fB\-\-ntasks\-per\-core\fR
    .TP
    \fBSLURM_NTASKS_PER_GPU\fR
    Same as \fB\-\-ntasks\-per\-gpu\fR
    .TP
    \fBSLURM_NTASKS_PER_NODE\fR
    Same as \fB\-\-ntasks\-per\-node\fR
    .TP
    \fBSLURM_NTASKS_PER_SOCKET\fR
    Same as \fB\-\-ntasks\-per\-socket\fR
    .TP
    \fBSLURM_OPEN_MODE\fR
    Same as \fB\-\-open\-mode\fR
    .TP
    \fBSLURM_OVERCOMMIT\fR
    Same as \fB\-O, \-\-overcommit\fR
    .TP
    \fBSLURM_OVERLAP\fR
    Same as \fB\-\-overlap\fR
    .TP
    \fBSLURM_PARTITION\fR
    Same as \fB\-p, \-\-partition\fR
    .TP
    \fBSLURM_PMI_KVS_NO_DUP_KEYS\fR
    If set, then PMI key\-pairs will contain no duplicate keys. MPI can use
    this variable to inform the PMI library that it will not use duplicate
    keys so PMI can skip the check for duplicate keys.
    This is the case for MPICH2 and reduces overhead in testing for duplicates
    for improved performance
    .TP
    .TP
    \fBSLURM_REQ_SWITCH\fR
    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 \fB\-\-switches\fR
    .TP
    \fBSLURM_RESERVATION\fR
    Same as \fB\-\-reservation\fR
    .TP
    \fBSLURM_RESV_PORTS\fR
    Same as \fB\-\-resv\-ports\fR
    .TP
    \fBSLURM_SIGNAL\fR
    Same as \fB\-\-signal\fR
    .TP
    \fBSLURM_STDERRMODE\fR
    Same as \fB\-e, \-\-error\fR
    .TP
    \fBSLURM_STDINMODE\fR
    Same as \fB\-i, \-\-input\fR
    .TP
    \fBSLURM_SPREAD_JOB\fR
    Same as \fB\-\-spread\-job\fR
    .TP
    \fBSLURM_SRUN_REDUCE_TASK_EXIT_MSG\fR
    if set and non-zero, successive task exit messages with the same exit code will
    be printed only once.
    .TP
    \fBSLURM_STEP_GRES\fR
    Same as \fB\-\-gres\fR (only applies to job steps, not to job allocations).
    Also see \fBSLURM_GRES\fR
    .TP
    \fBSLURM_STEP_KILLED_MSG_NODE_ID\fR=ID
    If set, only the specified node will log when the job or step are killed
    by a signal.
    .TP
    \fBSLURM_STDOUTMODE\fR
    Same as \fB\-o, \-\-output\fR
    .TP
    \fBSLURM_TASK_EPILOG\fR
    Same as \fB\-\-task\-epilog\fR
    .TP
    \fBSLURM_TASK_PROLOG\fR
    Same as \fB\-\-task\-prolog
    .TP
    \fBSLURM_TEST_EXEC\fR
    If defined, srun will verify existence of the executable program along with user
    execute permission on the node where srun was called before attempting to
    launch it on nodes in the step.
    .TP
    \fBSLURM_THREAD_SPEC\fR
    Same as \fB\-\-thread\-spec\fR
    Same as \fB\-\-use\-min\-nodes\fR
    .TP
    \fBSLURM_WAIT\fR
    Same as \fB\-W, \-\-wait\fR
    .TP
    \fBSLURM_WAIT4SWITCH\fR
    Max time waiting for requested switches. See \fB\-\-switches\fR
    .TP
    \fBSLURM_WCKEY\fR
    Same as \fB\-W, \-\-wckey\fR
    .TP
    \fBSLURM_WHOLE\fR
    Same as \fB\-\-whole\fR
    .TP
    \fBSLURM_WORKING_DIR\fR
    \fB\-D, \-\-chdir\fR
    .TP
    \fBSRUN_EXPORT_ENV\fR
    Same as \-\-export\fR, and will override any setting for \fBSLURM_EXPORT_ENV\fR.

    .SH "OUTPUT ENVIRONMENT VARIABLES"
    .PP
    srun will set some environment variables in the environment
    of the executing tasks on the remote compute nodes.
    These environment variables are:

    .TP 22
    \fBSLURM_*_HET_GROUP_#\fR
    For a heterogeneous job allocation, the environment variables are set separately
    for each component.
    .TP
    \fBSLURM_CLUSTER_NAME\fR
    Name of the cluster on which the job is executing.
    .TP
    \fBSLURM_CPU_BIND_VERBOSE\fR
    \-\-cpu\-bind verbosity (quiet,verbose).
    .TP
    \fBSLURM_CPU_BIND_TYPE\fR
    \-\-cpu\-bind type (none,rank,map_cpu:,mask_cpu:).
    .TP
    \fBSLURM_CPU_BIND_LIST\fR
    \-\-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).

    .TP
    \fBSLURM_CPU_FREQ_REQ\fR
    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
    \fIlow\fR, \fImedium\fR,\fIhighm1\fR or \fIhigh\fR for the frequency.
    \fBSLURM_DISTRIBUTION\fR
    Distribution type for the allocated jobs. Set the distribution
    with \-m, \-\-distribution.
    .TP
    \fBSLURM_GTIDS\fR
    Global task IDs running on this node.
    Zero origin and comma separated.
    .TP
    \fBSLURM_JOB_ACCOUNT\fR
    Account name associated of the job allocation.
    .TP
    \fBSLURM_JOB_CPUS_PER_NODE\fR
    Number of CPUS per node.
    .TP
    \fBSLURM_JOB_DEPENDENCY\fR
    Set to value of the \-\-dependency option.
    .TP
    \fBSLURM_JOB_ID\fR (and \fBSLURM_JOBID\fR for backwards compatibility)
    Job id of the executing job.

    .TP
    \fBSLURM_JOB_NAME\fR
    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).

    .TP
    \fBSLURM_JOB_PARTITION\fR
    Name of the partition in which the job is running.

    .TP
    \fBSLURM_JOB_QOS\fR
    Quality Of Service (QOS) of the job allocation.
    .TP
    \fBSLURM_JOB_RESERVATION\fR
    Advanced reservation containing the job allocation, if any.

    .TP
    \fBSLURM_LAUNCH_NODE_IPADDR\fR
    IP address of the node from which the task launch was
    initiated (where the srun command ran from).
    .TP
    \fBSLURM_LOCALID\fR
    Node local task ID for the process within a job.

    .TP
    \fBSLURM_MEM_BIND_LIST\fR
    \-\-mem\-bind map or mask list (<list of IDs or masks for this node>).
    .TP
    \fBSLURM_MEM_BIND_PREFER\fR
    \-\-mem\-bind prefer (prefer).
    .TP
    the job from the cloud. Each element in the set if colon separated and each
    set is comma separated. For example:
    .na
    SLURM_NODE_ALIASES\:=\:ec0:1.2.3.4:foo,ec1:1.2.3.5:bar
    .ad
    .TP
    \fBSLURM_NODEID\fR
    The relative node ID of the current node.
    .TP
    \fBSLURM_JOB_NODELIST\fR
    List of nodes allocated to the job.
    .TP
    \fBSLURM_NTASKS\fR (and \fBSLURM_NPROCS\fR for backwards compatibility)
    Total number of processes in the current job or job step.
    .TP
    \fBSLURM_HET_SIZE\fR
    Set to count of components in heterogeneous job.
    .TP
    \fBSLURM_PRIO_PROCESS\fR
    The scheduling priority (nice value) at the time of job submission.
    This value is propagated to the spawned processes.
    .TP
    \fBSLURM_PROCID\fR
    The MPI rank (or relative process ID) of the current process.
    .TP
    \fBSLURM_SRUN_COMM_HOST\fR
    IP address of srun communication host.
    .TP
    \fBSLURM_SRUN_COMM_PORT\fR
    srun communication port.
    .TP
    \fBSLURM_STEP_LAUNCHER_PORT\fR
    Step launcher port.
    .TP
    \fBSLURM_STEP_NODELIST\fR
    List of nodes allocated to the step.
    .TP
    \fBSLURM_STEP_NUM_NODES\fR
    Number of nodes allocated to the step.
    .TP
    \fBSLURM_STEP_NUM_TASKS\fR
    Number of processes in the job step or whole heterogeneous job step.
    .TP
    \fBSLURM_STEP_TASKS_PER_NODE\fR
    Number of processes per node within the step.
    .TP
    \fBSLURM_STEP_ID\fR (and \fBSLURM_STEPID\fR for backwards compatibility)
    The step ID of the current job.
    .TP
    \fBSLURM_SUBMIT_DIR\fR
    The directory from which \fBsrun\fR was invoked or, if applicable, the
    directory specified by the \fB\-D, \-\-chdir\fR option.
    tasks and the fourth node will execute one task.

    .TP
    \fBSLURM_TOPOLOGY_ADDR\fR
    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.
    .TP
    \fBSLURM_TOPOLOGY_ADDR_PATTERN\fR
    This is set only if the system has the topology/tree plugin configured.
    The value will be set component types listed in \fBSLURM_TOPOLOGY_ADDR\fR.
    Each component will be identified as either "switch" or "node".
    A period is used to separate each hardware component type.
    .TP
    \fBSLURM_UMASK\fR
    The \fIumask\fR in effect when the job was submitted.
    .TP
    \fBSLURMD_NODENAME\fR
    Name of the node running the task. In the case of a parallel job executing on
    multiple compute nodes, the various tasks will have this environment variable
    set to different values on each compute node.
    .TP
    \fBSRUN_DEBUG\fR
    Set to the logging level of the \fBsrun\fR command.
    Default value is 3 (info level).
    The value is incremented or decremented based upon the \-\-verbose and
    \-\-quiet options.

    .SH "SIGNALS AND ESCAPE SEQUENCES"
    Signals sent to the \fBsrun\fR command are automatically forwarded to
    the tasks it is controlling with a few exceptions. The escape sequence
    \fB<control\-c>\fR will report the state of all tasks associated with
    the \fBsrun\fR command. If \fB<control\-c>\fR 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 \fB<control\-c>\fR is received, the srun program will be
    terminated without waiting for remote tasks to exit or their I/O to
    complete.

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

    .SH "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
    See \fIhttps://slurm.schedmd.com/mpi_guide.html\fR
    for more information on use of these various MPI implementation
    with Slurm.

    .SH "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:
    .TP
    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".
    .TP
    Executable
    The name of the program to execute.
    May be fully qualified pathname if desired.
    .TP
    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.
    .PP
    For example:
    .nf
    ###################################################################
    # 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
    .nf

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

    .fi
    .PP
    The srun \fB\-r\fR 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.

    .nf

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

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

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

    .nf

    > 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

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

    # Generate Machinefile for mpi 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

    .fi
    .PP
    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.

    .nf

    > 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

    .fi
    .PP
    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.

    .nf

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

    .PP
    This example shows how to launch an application called "server" with one task,
    8 CPUs and 16 GB of memory (2 GB per CPU) plus another application called
    "client" with 16 tasks, 1 CPU per task (the default) and 1 GB of memory per
    task.

    .nf

    > srun \-n1 \-c16 \-\-mem\-per\-cpu=1gb server : \-n16 \-\-mem\-per\-cpu=1gb client
    .fi

    .SH "COPYING"
    Copyright (C) 2006\-2007 The Regents of the University of California.
    Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
    .br
    Copyright (C) 2008\-2010 Lawrence Livermore National Security.
    .br
    Copyright (C) 2010\-2015 SchedMD LLC.
    .LP
    This file is part of Slurm, a resource management program.
    For details, see <https://slurm.schedmd.com/>.
    .LP
    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.
    .LP
    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.

    .SH "SEE ALSO"
    \fBsalloc\fR(1), \fBsattach\fR(1), \fBsbatch\fR(1), \fBsbcast\fR(1),
    \fBscancel\fR(1), \fBscontrol\fR(1), \fBsqueue\fR(1), \fBslurm.conf\fR(5),
    \fBsched_setaffinity\fR (2), \fBnuma\fR (3)
    \fBgetrlimit\fR (2)