doc/man/man1/srun.1

.TH "srun" "1" "SLURM 2.0" "April 2009" "SLURM Commands"

.SH "NAME"
srun \- Run parallel jobs

.SH "SYNOPSIS"
\fBsrun\fR            [\fIOPTIONS\fR...]  \fIexecutable \fR[\fIargs\fR...]

.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.

.SH "OPTIONS"
.LP

.TP
\fB\-\-acctg\-freq\fR=<\fIseconds\fR>
Define the job accounting sampling interval.
This can be used to override the \fIJobAcctGatherFrequency\fR parameter in SLURM's
configuration file, \fIslurm.conf\fR.
A value of zero disables real the periodic job sampling and provides accounting
information only on job termination (reducing SLURM interference with the job).

.TP
\fB\-B\fR \fB\-\-extra\-node\-info\fR=<\fIsockets\fR[:\fIcores\fR[:\fIthreads\fR]]>
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.
As with \-\-nodes, each value can be a single number or a range (e.g. min\-max).
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:
.nf
    \fB\-\-sockets\-per\-node\fR=<\fIsockets\fR>
    \fB\-\-cores\-per\-socket\fR=<\fIcores\fR>
    \fB\-\-threads\-per\-core\fR=<\fIthreads\fR>
.fi
When the task/affinity plugin is enabled,
specifying an allocation in this manner also instructs SLURM to use
a CPU affinity mask to guarantee the request is filled as specified.
NOTE: Support for these options are configuration dependent. 
The task/affinity plugin must be configured.
In addition either select/linear or select/cons_res plugin must be 
configured.
If select/cons_res is configured, it must have a parameter of CR_Core, 
CR_Core_Memory, CR_Socket, or CR_Socket_Memory. 

.TP
\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).
(If that time is already past, the next day is assumed.)
You may also specify \fImidnight\fR, \fInoon\fR, or
\fIteatime\fR (4pm) and you can have a time\-of\-day suffixed
with \fIAM\fR or \fIPM\fR 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 \fIMMDDYY\fR or \fIMM/DD/YY\fR
\fIYYYY-MM-DD\fR. Combine date and time using the following
format \fIYYYY\-MM\-DD[THH:MM[:SS]]\fR. You can also
give times like \fInow + count time\-units\fR, where the time\-units
can be \fIseconds\fR (default), \fIminutes\fR, \fIhours\fR,
\fIdays\fR, or \fIweeks\fR and you can tell SLURM to run
the job today with the keyword \fItoday\fR and to run the
job tomorrow with the keyword \fItomorrow\fR.
The value may be changed after job submission using the
\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.
.RE

.TP
\fB\-\-checkpoint\fR=<\fItime\fR>
Specifies the interval between creating checkpoints of the job step. 
By default, the job step will no checkpoints created.
Acceptable time formats include "minutes", "minutes:seconds", 
"hours:minutes:seconds", "days\-hours", "days\-hours:minutes" and 
"days\-hours:minutes:seconds".

.TP
\fB\-\-checkpoint\-dir\fR=<\fIdirectory\fR>
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.

.TP
\fB\-\-comment\fR=<\fIstring\fR>
An arbitrary comment.

.TP
\fB\-C\fR, \fB\-\-constraint\fR=<\fIlist\fR>
Specify a list of constraints. 
The constraints are features that have been assigned to the nodes by 
the slurm administrator. 
The \fIlist\fR of constraints may include multiple features separated 
by ampersand (AND) and/or vertical bar (OR) operators.
For example: \fB\-\-constraint="opteron&video"\fR or 
\fB\-\-constraint="fast|faster"\fR.
In the first example, only nodes having both the feature "opteron" AND
the feature "video" will be used.
There is no mechanism to specify that you want one node with feature
"opteron" and another node with feature "video" in that case that no
node has both features.
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.
A request can also specify the number of nodes needed with some feature
by appending an asterisk and count after the feature name. 
For example "\fBsrun \-\-nodes=16 \-\-constraint=graphics*4 ..."\fR 
indicates that the job requires 16 nodes at that at least four of those
nodes must have the feature "graphics."
Constraints with node counts may only be combined with AND operators.
If no nodes have the requested features, then the job will be rejected 
by the slurm job manager.

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

.TP
\fB\-\-core\fR=<\fItype\fR>
Adjust corefile format for parallel job. If possible, srun will set
up the environment for the job such that a corefile format other than
full core dumps is enabled. If run with type = "list", srun will
print a list of supported corefile format types to stdout and exit.

.TP
\fB\-\-cpu_bind\fR=[{\fIquiet,verbose\fR},]\fItype\fR
Bind tasks to CPUs. Used only when the task/affinity plugin is enabled.
The configuration parameter \fBTaskPluginParam\fR may override these options.
For example, if \fBTaskPluginParam\fR 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 \fB\-\-cpu_bind\fR
is in use:
.nf
        SLURM_CPU_BIND_VERBOSE
        SLURM_CPU_BIND_TYPE
        SLURM_CPU_BIND_LIST
.fi

See the \fBENVIRONMENT VARIABLE\fR section for a more detailed description
of the individual SLURM_CPU_BIND* variables.

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.

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, us the
\fB\-\-exclusive\fR 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.
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:
.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)
.TP
.B 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.
.TP
.B 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.
.TP
.B mask_cpu:<list>
Bind by setting CPU masks on tasks as specified
where <list> is <mask1>,<mask2>,...<maskN>.
CPU masks are \fBalways\fR interpreted as hexadecimal values but can be
preceded with an optional '0x'.
Not supported unless the entire node is allocated to the job.
.TP
.B rank_ldom
Bind to a NUMA locality domain by rank
.TP
.B 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 areinterpreted as hexadecimal values.
Not supported unless the entire node is allocated to the job.
.TP
.B 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 \fBalways\fR interpreted as hexadecimal
values but can be preceded with an optional '0x'.
Not supported unless the entire node is allocated to the job.
.TP
.B sockets
Automatically generate masks binding tasks to sockets.
If the number of tasks differs from the number of allocated sockets
this can result in sub\-optimal binding.
.TP
.B 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.
.TP
.B 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.
.TP
.B 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.
.TP
.B help
Show this help message
.RE

.TP
\fB\-c\fR, \fB\-\-cpus\-per\-task\fR=<\fIncpus\fR>
Request that \fIncpus\fR be allocated \fBper process\fR. 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 \fB\-c\fR is specified without \fB\-n\fR, as many 
tasks will be allocated per node as possible while satisfying
the \fB\-c\fR 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 \fB\-\-exclusive\fR option.

.TP
\fB\-D\fR, \fB\-\-chdir\fR=<\fIpath\fR>
have the remote processes do a chdir to \fIpath\fR before beginning
execution. The default is to chdir to the current working directory
of the \fBsrun\fR process.

.TP
\fB\-d\fR, \fB\-\-slurmd\-debug\fR=<\fIlevel\fR>
Specify a debug level for slurmd(8). \fIlevel\fR 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. 

.TP
\fB\-e\fR, \fB\-\-error\fR=<\fImode\fR>
Specify how stderr is to be redirected. By default in interactive mode,
.B srun
redirects stderr to the same file as stdout, if one is specified. The
\fB\-\-error\fR option is provided to allow stdout and stderr to be
redirected to different locations.
See \fBIO Redirection\fR below for more options.
If the specified file already exists, it will be overwritten.

.TP
\fB\-E\fR, \fB\-\-preserve-env\fR
Pass the current values of environment variables SLURM_NNODES and 
SLURM_NPROCS through to the \fIexecutable\fR, rather than computing them
from commandline parameters.

.TP
\fB\-\-epilog\fR=<\fIexecutable\fR>
\fBsrun\fR will run \fIexecutable\fR just after the job step completes.
The command line arguments for \fIexecutable\fR will be the command
and arguments of the job step.  If \fIexecutable\fR is "none", then
no epilog will be run.  This parameter overrides the SrunEpilog
parameter in slurm.conf.

.TP
\fB\-\-exclusive\fR
When used to initiate a job, the job allocation cannot share nodes with 
other running jobs.  This is the oposite of \-\-share, whichever option 
is seen last on the command line will win.  (The default shared/exclusive 
behaviour depends on system configuration.)

This option can also be used when initiating more than job step within 
an existing resource allocation and 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 \fB\-\-exclusive\fR option is used plus
task affinity is configured. Since resource management is provided by 
processor, the \fB\-\-ntasks\fR option must be specified, but the 
following options should NOT be specified \fB\-\-nodes\fR, 
\fB\-\-relative\fR, \fB\-\-distribution\fR=\fIarbitrary\fR.
See \fBEXAMPLE\fR below.

.TP
\fB\-\-gid\fR=<\fIgroup\fR>
If \fBsrun\fR is run as root, and the \fB\-\-gid\fR option is used, 
submit the job with \fIgroup\fR's group access permissions.  \fIgroup\fR 
may be the group name or the numerical group ID.

.\".TP
.\"NOTE: Do not document feature until user release mechanism is available.
.\"\-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.

.TP
\fB\-\-help\fR
Display help information and exit.

.TP
\fB\-\-hint\fR=<\fItype\fR>
Bind tasks according to application hints
.RS
.TP
.B compute_bound
Select settings for compute bound applications:
use all cores in each physical CPU
.TP
.B memory_bound
Select settings for memory bound applications:
use only one core in each physical CPU
.TP
.B [no]multithread
[don't] use extra threads with in-core multi-threading
which can benefit communication intensive applications
.TP
.B help
show this help message
.RE

.TP
\fB\-I\fR, \fB\-\-immediate\fR[=<\fIseconds\fR>]
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, \fB\-\-immediate\fR is off, and the command
will block until resources become available.

.TP
\fB\-i\fR, \fB\-\-input\fR=<\fImode\fR>
Specify how stdin is to redirected. By default,
.B srun
redirects stdin from the terminal all tasks. See \fBIO Redirection\fR
below for more options.
For OS X, the poll() function does not support stdin, so input from 
a terminal is not possible.

.TP
\fB\-J\fR, \fB\-\-job\-name\fR=<\fIjobname\fR>
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 \fBexecutable\fR program's name.

.TP
\fB\-\-jobid\fR=<\fIjobid\fR>
Initiate a job step under an already allocated job with job id \fIid\fR.
Using this option will cause \fBsrun\fR to behave exactly as if the
SLURM_JOB_ID environment variable was set.

.TP
\fB\-K\fR, \fB\-\-kill\-on\-bad\-exit\fR
Terminate a job if any task exits with a non\-zero exit code.

.TP
\fB\-k\fR, \fB\-\-no\-kill\fR
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. The 
active job step (MPI job) will almost certainly suffer a fatal error, 
but subsequent job steps may be run if this option is specified. The
default action is to terminate job upon node failure.

.TP
\fB\-l\fR, \fB\-\-label\fR
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
\fBsrun\fR.
The \fB\-\-label\fR option will prepend lines of output with the remote
task id.

.TP
\fB\-L\fR, \fB\-\-licenses\fR=<\fBlicense\fR>
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 an asterisk and count 
(the default count is one).
Multiple license names should be comma separated (e.g.
"\-\-licenses=foo*4,bar").

.TP
\fB\-m\fR, \fB\-\-distribution\fR=
<\fIblock\fR|\fIcyclic\fR|\fIarbitrary\fR|\fIplane=<options>\fR>
Specify an alternate distribution method for remote processes.
.RS
.TP
.B block
The block method of distribution will allocate processes in\-order to
the cpus on a node. If the number of processes exceeds the number of 
cpus on all of the nodes in the allocation then all nodes will be 
utilized. For example, consider an allocation of three nodes each with 
two cpus. A four\-process block distribution request will distribute 
those processes to the nodes with processes one and two on the first 
node, process three on the second node, and process four on the third node.  
Block distribution is the default behavior if the number of tasks 
exceeds the number of nodes requested.
.TP
.B cyclic
The cyclic method distributes processes in a round\-robin fashion across
the allocated nodes. That is, process one will be allocated to the first
node, process two to the second, and so on. This is the default behavior
if the number of tasks is no larger than the number of nodes requested.
.TP
.B 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.
For more details (including examples and diagrams), please see
.br
https://computing.llnl.gov/linux/slurm/mc_support.html
.br
and
.br
https://computing.llnl.gov/linux/slurm/dist_plane.html.
.TP
.B 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.  If requesting tasks
(\-n) your tasks will be laid out on the nodes in the order of the file.
.RE

.TP
\fB\-\-mail\-type\fR=<\fItype\fR>
Notify user by email when certain event types occur. 
Valid \fItype\fR values are BEGIN, END, FAIL, ALL (any state change). 
The user to be notified is indicated with \fB\-\-mail\-user\fR. 

.TP
\fB\-\-mail\-user\fR=<\fIuser\fR>
User to receive email notification of state changes as defined by 
\fB\-\-mail\-type\fR.
The default value is the submitting user.

.TP
\fB\-\-mem\fR=<\fIMB\fR>
Specify the real memory required per node in MegaBytes.
Default value is \fBDefMemPerNode\fR and the maximum value is
\fBMaxMemPerNode\fR. If configured, both of parameters can be
seen using the \fBscontrol show config\fR command.
This parameter would generally be used of whole nodes
are allocated to jobs (\fBSelectType=select/linear\fR).
Also see \fB\-\-mem\-per\-cpu\fR.
\fB\-\-mem\fR and \fB\-\-mem\-per\-cpu\fR are mutually exclusive.

.TP
\fB\-\-mem\-per\-cpu\fR=<\fIMB\fR>
Mimimum memory required per allocated CPU in MegaBytes.
Default value is \fBDefMemPerCPU\fR and the maximum value is
\fBMaxMemPerCPU\fR. If configured, both of parameters can be 
seen using the \fBscontrol show config\fR command.
This parameter would generally be used of individual processors
are allocated to jobs (\fBSelectType=select/cons_res\fR).
Also see \fB\-\-mem\fR.
\fB\-\-mem\fR and \fB\-\-mem\-per\-cpu\fR are mutually exclusive.

.TP
\fB\-\-mem_bind\fR=[{\fIquiet,verbose\fR},]\fItype\fR
Bind tasks to memory. Used only when the task/affinity plugin is enabled 
and the NUMA memory functions are available.
\fBNote that the resolution of CPU and memory binding 
may differ on some architectures.\fR 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. \fBThe use of any type other than 
"none" or "local" is not recommended.\fR
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 \fB\-\-mem_bind\
is in use:

.nf
        SLURM_MEM_BIND_VERBOSE
        SLURM_MEM_BIND_TYPE
        SLURM_MEM_BIND_LIST
.fi

See the \fBENVIRONMENT VARIABLES\fR section for a more detailed description
of the individual SLURM_MEM_BIND* variables.

Supported options include:
.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]
don't bind tasks to memory (default)
.TP
.B rank
bind by task rank (not recommended)
.TP
.B local
Use memory local to the processor in use
.TP
.B 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)
.TP
.B mask_mem:<list>
bind by setting memory masks on tasks as specified
where <list> is <mask1>,<mask2>,...<maskN>.
memory masks are \fBalways\fR 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.
.TP
.B help
show this help message
.RE

.TP
\fB\-\-mincores\fR=<\fIn\fR>
Specify a minimum number of cores per socket.

.TP
\fB\-\-mincpus\fR=<\fIn\fR>
Specify a minimum number of logical cpus/processors per node.

.TP
\fB\-\-minsockets\fR=<\fIn\fR>
Specify a minimum number of sockets (physical processors) per node.

.TP
\fB\-\-minthreads\fR=<\fIn\fR>
Specify a minimum number of threads per core.

.TP
\fB\-\-msg\-timeout\fR=<\fIseconds\fR>
Modify the job launch message timeout.
The default value is \fBMessageTimeout\fR in the SLURM configuration file slurm.conf. 
Changes to this are typically not recommended, but could be useful to diagnose problems.

.TP
\fB\-\-mpi\fR=<\fImpi_type\fR>
Identify the type of MPI to be used. May result in unique initiation 
procedures.
.RS
.TP
.B list
Lists available mpi types to choose from.
.TP
.B lam
Initiates one 'lamd' process per node and establishes necessary
environment variables for LAM/MPI.
.TP
.B 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.
.TP
.B mpichgm
For use with Myrinet.
.TP
.B mvapich
For use with Infiniband.
.TP
.B openmpi
For use with OpenMPI.
.TP
.B none
No special MPI processing. This is the default and works with 
many other versions of MPI.
.RE

.TP
\fB\-\-multi\-prog\fR
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 \fBMULTIPLE PROGRAM CONFIGURATION\fR
below for details on the configuration file contents. 

.TP
\fB\-N\fR, \fB\-\-nodes\fR=<\fIminnodes\fR[\-\fImaxnodes\fR]>
Request that a minimum of \fIminnodes\fR nodes be allocated to this job.
The scheduler may decide to launch the job on more than \fIminnodes\fR nodes.
A limit on the maximum node count may be specified with \fImaxnodes\fR
(e.g. "\-\-nodes=2\-4").  The minimum and maximum node count may be the
same to specify a specific number of nodes (e.g. "\-\-nodes=2\-2" will ask
for two and ONLY two nodes).
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 \fBSLURM_NNODES\fR will be set to the count of nodes actually 
allocated to the job. See the \fBENVIRONMENT VARIABLES \fR section 
for more information.  If \fB\-N\fR is not specified, the default
behavior is to allocate enough nodes to satisfy the requirements of
the \fB\-n\fR and \fB\-c\fR options.
The job will be allocated as many nodes as possible within the range specified
and without delaying the initiation of the job.

.TP
\fB\-n\fR, \fB\-\-ntasks\fR=<\fInumber\fR>
Specify the number of tasks to run. Request that \fBsrun\fR
allocate resources for \fIntasks\fR tasks.  
The default is one task per socket or core (depending upon the value 
of the \fISelectTypeParameters\fR parameter in slurm.conf), but note 
that the \fB\-\-cpus\-per\-task\fR option will change this default.

.TP
\fB\-\-network\fR=<\fItype\fR>
Specify the communication protocol to be used. 
This option is supported on AIX systems.
Since POE is used to launch tasks, this option is not normally used or 
is specified using the \fBSLURM_NETWORK\fR environment variable.
The interpretation of \fItype\fR is system dependent.
For systems with an IBM Federation switch, the following 
comma\-separated and case insensitive types are recognized:
\fBIP\fR (the default is user\-space), \fBSN_ALL\fR, \fBSN_SINGLE\fR, 
\fBBULK_XFER\fR and adapter names  (e.g. \fBSNI0\fR and \fBSNI1\fR). 
For more information, on IBM systems see \fIpoe\fR documentation on
the environment variables \fBMP_EUIDEVICE\fR and \fBMP_USE_BULK_XFER\fR.
Note that only four jobs steps may be active at once on a node with the 
\fBBULK_XFER\fR option due to limitations in the Federation switch driver.

.TP
\fB\-\-nice\fR[=\fIadjustment\fR]
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 \fISchedulerType=sched/wiki\fR or 
\fISchedulerType=sched/wiki2\fR.

.TP
\fB\-\-ntasks\-per\-core\fR=<\fIntasks\fR>
Request that no more than \fIntasks\fR be invoked on each core.
Similar to \fB\-\-ntasks\-per\-node\fR except at the core level
instead of the node level.  Masks will automatically be generated
to bind the tasks to specific core unless \fB\-\-cpu_bind=none\fR
is specified.
NOTE: This option is not supported unless
\fISelectTypeParameters=CR_Core\fR or
\fISelectTypeParameters=CR_Core_Memory\fR is configured.

.TP
\fB\-\-ntasks\-per\-socket\fR=<\fIntasks\fR>
Request that no more than \fIntasks\fR be invoked on each socket.
Similar to \fB\-\-ntasks\-per\-node\fR except at the socket level
instead of the node level.  Masks will automatically be generated
to bind the tasks to specific sockets unless \fB\-\-cpu_bind=none\fR
is specified.
NOTE: This option is not supported unless
\fISelectTypeParameters=CR_Socket\fR or
\fISelectTypeParameters=CR_Socket_Memory\fR is configured.

.TP
\fB\-\-ntasks\-per\-node\fR=<\fIntasks\fR>
Request that no more than \fIntasks\fR be invoked on each node.
This is similar to using \fB\-\-cpus\-per\-task\fR=\fIncpus\fR
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 ntasks 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.

.TP
\fB\-O\fR, \fB\-\-overcommit\fR
Overcommit resources.  Normally, \fBsrun\fR will allocate one task
per processor.  By specifying \fB\-\-overcommit\fR you are explicitly
allowing more than one task per processor.  However no more than
\fBMAX_TASKS_PER_NODE\fR tasks are permitted to execute per node.

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

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

.TP
\fB\-\-open\-mode\fR=<\fIappend|truncate\fR>
Open the output and error files using append or truncate mode as specified.
The default value is specified by the system configuration parameter
\fIJobFileAppend\fR.

.TP
\fB\-P\fR, \fB\-\-dependency\fR=<\fIdependency_list\fR>
Defer the start of this job until the specified dependencies have been
satisfied completed.
<\fIdependency_list\fR> is of the form 
<\fItype:job_id[:job_id][,type:job_id[:job_id]]\fR>.
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.
.PD
.RS
.TP
\fBafter:job_id[:jobid...]\fR
This job can begin execution after the specified jobs have begun
execution.
.TP
\fBafterany:job_id[:jobid...]\fR
This job can begin execution after the specified jobs have terminated.
.TP
\fBafternotok:job_id[:jobid...]\fR
This job can begin execution after the specified jobs have terminated
in some failed state (non-zero exit code, node failure, timed out, etc).
.TP
\fBafterok:job_id[:jobid...]\fR
This job can begin execution after the specified jobs have successfully
executed (ran to completion with non-zero exit code).
.TP
\fBsingleton\fR
This job can begin execution after any previously launched jobs sharing the same
job name and user have terminated.
.RE

.TP
\fB\-p\fR, \fB\-\-partition\fR=<\fIpartition name\fR>
Request a specific partition for the resource allocation.  If not specified,
the default behaviour is to allow the slurm controller to select the default
partition as designated by the system administrator.

.TP
\fB\-\-prolog\fR=<\fIexecutable\fR>
\fBsrun\fR will run \fIexecutable\fR just before launching the job step.
The command line arguments for \fIexecutable\fR will be the command
and arguments of the job step.  If \fIexecutable\fR is "none", then
no prolog will be run.  This parameter overrides the SrunProlog
parameter in slurm.conf.

.TP
\fB\-\-propagate\fR[=\fIrlimits\fR]
Allows users to specify which of the modifiable (soft) resource limits
to propagate to the compute nodes and apply to their jobs.  If
\fIrlimits\fR 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):
.RS
.TP 10
\fBALL\fR
All limits listed below
.TP
\fBAS\fR
The maximum address space for a processes
.TP
\fBCORE\fR
The maximum size of core file
.TP
\fBCPU\fR
The maximum amount of CPU time
.TP
\fBDATA\fR
The maximum size of a process's data segment
.TP
\fBFSIZE\fR
The maximum size of files created
.TP
\fBMEMLOCK\fR
The maximum size that may be locked into memory
.TP
\fBNOFILE\fR
The maximum number of open files
.TP
\fBNPROC\fR
The maximum number of processes available
.TP
\fBRSS\fR
The maximum resident set size
.TP
\fBSTACK\fR
The maximum stack size
.RE

.TP
\fB\-\-pty\fR
Execute task zero in pseudo terminal.
Implicitly sets \fB\-\-unbuffered\fR.
Implicitly sets \fB\-\-error\fR and \fB\-\-output\fR to /dev/null 
for all tasks except task zero.
Not currently supported on AIX platforms.

.TP
\fB\-Q\fR, \fB\-\-quiet\fR
Suppress informational messages from srun. Errors will still be displayed.

.TP
\fB\-q\fR, \fB\-\-quit\-on\-interrupt\fR
Quit immediately on single SIGINT (Ctrl\-C). Use of this option
disables the status feature normally available when \fBsrun\fR receives 
a single Ctrl\-C and causes \fBsrun\fR to instead immediately terminate the
running job. 

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

.TP
\fB\-\-resv-ports\fR
Reserve communication ports for this job.
Used for OpenMPI.

.TP
\fB\-\-reservation\fR=<\fIname\fR>
Allocate resources for the job from the named reservation.

.TP
\fB\-\-restart\-dir\fR=<\fIdirectory\fR>
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).

.TP
\fB\-s\fR, \fB\-\-share\fR
The job can share nodes with other running jobs. This may result in faster job 
initiation and higher system utilization, but lower application performance.

.TP
\fB\-T\fR, \fB\-\-threads\fR=<\fInthreads\fR>
Request that \fBsrun\fR
use \fInthreads\fR to initiate and control the parallel job. The 
default value is the smaller of 60 or the number of nodes allocated.
This should only be used to set a low thread count for testing on 
very small memory computers.

.TP
\fB\-t\fR, \fB\-\-time\fR=<\fItime\fR>
Set a limit on the total run time of the job step.  If the
requested time limit exceeds the partition's time limit, the job will
be left in a PENDING state (possibly indefinitely).  The default time
limit is the partition's time limit.  When the time limit is reached,
all of the job's tasks are sent SIGTERM followed by SIGKILL.  The
interval between signals is specified by the SLURM configuration
parameter \fBKillWait\fR.  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".

.TP
\fB\-\-task\-epilog\fR=<\fIexecutable\fR>
The \fBslurmstepd\fR daemon will run \fIexecutable\fR 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.

.TP
\fB\-\-task\-prolog\fR=<\fIexecutable\fR>
The \fBslurmstepd\fR daemon will run \fIexecutable\fR 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.

.TP
\fB\-\-tmp\fR=<\fIMB\fR>
Specify a minimum amount of temporary disk space.

.TP
\fB\-U\fR, \fB\-\-account\fR=<\fIaccount\fR>
Change resource use 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.

.TP
\fB\-u\fR, \fB\-\-unbuffered\fR
Do not line buffer stdout from remote tasks. This option cannot be used
with \fI\-\-label\fR.

.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.

.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.

.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
parameter in the slurm configuration file (see \fBslurm.conf(5)\fR). 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.

.TP
\fB\-w\fR, \fB\-\-nodelist\fR=<\fIhost1,host2,...\fR or \fIfilename\fR>
Request a specific list of hosts. The job will contain \fIat least\fR
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.

.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.

.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.

.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.

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

.TP
\fB\-\-blrts\-image\fR=<\fIpath\fR>
Path to blrts image for bluegene block.  BGL only.
Default from \fIblugene.conf\fR if not set.

.TP
\fB\-\-cnload\-image\fR=<\fIpath\fR>
Path to compute node image for bluegene block.  BGP only.
Default from \fIblugene.conf\fR if not set.

.TP
\fB\-\-conn\-type\fR=<\fItype\fR>
Require the partition connection type to be of a certain type.  
On Blue Gene the acceptable of \fItype\fR are MESH, TORUS and NAV.  
If NAV, or if not set, then SLURM will try to fit a TORUS else MESH.
You should not normally set this option.
SLURM will normally allocate a TORUS if possible for a given geometry.
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.

.TP
\fB\-g\fR, \fB\-\-geometry\fR=<\fIXxYxZ\fR>
Specify the geometry requirements for the job. The three numbers 
represent the required geometry giving dimensions in the X, Y and 
Z directions. For example "\-\-geometry=2x3x4", specifies a block 
of nodes having 2 x 3 x 4 = 24 nodes (actually base partitions on 
Blue Gene).

.TP
\fB\-\-ioload\-image\fR=<\fIpath\fR>
Path to io image for bluegene block.  BGP only.
Default from \fIblugene.conf\fR if not set.

.TP
\fB\-\-linux\-image\fR=<\fIpath\fR>
Path to linux image for bluegene block.  BGL only.
Default from \fIblugene.conf\fR if not set.

.TP
\fB\-\-mloader\-image\fR=<\fIpath\fR>
Path to mloader image for bluegene block.
Default from \fIblugene.conf\fR if not set.

.TP
\fB\-R\fR, \fB\-\-no\-rotate\fR
Disables rotation of the job's requested geometry in order to fit an 
appropriate partition.
By default the specified geometry can rotate in three dimensions.

.TP
\fB\-\-ramdisk\-image\fR=<\fIpath\fR>
Path to ramdisk image for bluegene block.  BGL only.
Default from \fIblugene.conf\fR if not set.

.TP
\fB\-\-reboot\fR
Force the allocated nodes to reboot before starting the job.

.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
will block until the resources are free to run the job. If the
\fB\-I\fR (\fB\-\-immediate\fR) option is specified
.B srun
will terminate if resources are not immediately available.
.PP
When initiating remote processes
.B srun
will propagate the current working directory, unless
\fB\-\-chdir\fR=<\fIpath\fR> is specified, in which case \fIpath\fR will
become the working directory for the remote processes.
.PP
The \fB\-n\fB, \fB\-c\fR, and \fB\-N\fR options control how CPUs  and
nodes will be allocated to the job. When specifying only the number
of processes to run with \fB\-n\fR, a default of one CPU per process
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. 
For OS X, the poll() function does not support stdin, so input from 
a terminal is not possible.
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).
.TP
\fItaskid\fR
stdout and/or stderr are redirected from only the task with relative
id equal to \fItaskid\fR, where 0 <= \fItaskid\fR <= \fIntasks\fR,
where \fIntasks\fR is the total number of tasks in the current job step.
stdin is redirected from the stdin of \fBsrun\fR to this same task.
This file will be written on the node executing the task.
.TP
\fIfilename\fR
\fBsrun\fR 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.  \fIfilename\fR refers to a path on the host
that runs \fBsrun\fR.  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.
.TP
format string
\fBsrun\fR 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 \fBsrun\fR executes.
.RS 10
.TP
%J
jobid.stepid of the running job. (e.g. "128.0")
.TP
%j 
jobid of the running job. 
.TP
%s
stepid of the running job.
.TP
%N
short hostname. This will create a separate IO file per node.
.TP
%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.
.TP
%t
task identifier (rank) relative to current job. This will create a
separate IO file per task.
.PP
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:
.TP 15
job%J.out
job128.0.out
.TP
job%4j.out
job0128.out
.TP
job%j\-%2t.out 
job128\-00.out, job128\-01.out, ...
.PP
.RS -10
.PP

.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
\fBPMI_TIME\fR
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.
.TP
\fBSLURM_CONF\fR
The location of the SLURM configuration file.
.TP
\fBSLURM_ACCOUNT\fR
Same as \fB\-U, \-\-account\fR
.TP
\fBSLURM_ACCTG_FREQ\fR
Same as \fB\-\-acctg\-freq\fR
.TP
\fBSLURM_CHECKPOINT\fR
Same as \fB\-\-checkpoint\fR
.TP
\fBSLURM_CHECKPOINT_DIR\fR
Same as \fB\-\-checkpoint\-dir\fR
.TP
\fBSLURM_CONN_TYPE\fR
Same as \fB\-\-conn\-type\fR
.TP
\fBSLURM_CORE_FORMAT\fR
Same as \fB\-\-core\fR
.TP
\fBSLURM_CPU_BIND\fR
Same as \fB\-\-cpu_bind\fR
.TP
\fBSLURM_CPUS_PER_TASK\fR
Same as \fB\-c, \-\-ncpus\-per\-task\fR
.TP
\fBSLURM_DEBUG\fR
Same as \fB\-v, \-\-verbose\fR
.TP
\fBSLURMD_DEBUG\fR
Same as \fB\-d, \-\-slurmd\-debug\fR
.TP
\fBSLURM_DEPENDENCY\fR
\fB\-P, \-\-dependency\fR=<\fIjobid\fR>
.TP
\fBSLURM_DISABLE_STATUS\fR
Same as \fB\-X, \-\-disable\-status\fR
.TP
\fBSLURM_DIST_PLANESIZE\fR
Same as \fB\-m plane\fR
.TP
\fBSLURM_DISTRIBUTION\fR
Same as \fB\-m, \-\-distribution\fR
.TP
\fBSLURM_EPILOG\fR
Same as \fB\-\-epilog\fR
.TP
\fBSLURM_EXCLUSIVE\fR
Same as \fB\-\-exclusive\fR
.TP
\fBSLURM_GEOMETRY\fR
Same as \fB\-g, \-\-geometry\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_LABELIO\fR
Same as \fB\-l, \-\-label\fR
.TP
\fBSLURM_MEM_BIND\fR
Same as \fB\-\-mem_bind\fR
.TP
\fBSLURM_NETWORK\fR
Same as \fB\-\-network\fR
.TP
\fBSLURM_NNODES\fR
Same as \fB\-N, \-\-nodes\fR
.TP
\fBSLURM_NTASKS_PER_CORE\fR
Same as \fB\-\-ntasks\-per\-core\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_NO_ROTATE\fR
Same as \fB\-R, \-\-no\-rotate\fR
.TP
\fBSLURM_NPROCS\fR
Same as \fB\-n, \-\-ntasks\fR
.TP
\fBSLURM_OPEN_MODE\fR
Same as \fB\-\-open\-mode\fR
.TP
\fBSLURM_OVERCOMMIT\fR
Same as \fB\-O, \-\-overcommit\fR
.TP
\fBSLURM_PARTITION\fR
Same as \fB\-p, \-\-partition\fR
.TP
\fBSLURM_PROLOG\fR
Same as \fB\-\-prolog\fR
.TP
\fBSLURM_REMOTE_CWD\fR
Same as \fB\-D, \-\-chdir=\fR
.TP
\fBSLURM_RESTART_DIR\fR
Same as \fB\-\-restart-dir\fR
.TP
\fBSLURM_STDERRMODE\fR
Same as \fB\-e, \-\-error\fR
.TP
\fBSLURM_STDINMODE\fR
Same as \fB\-i, \-\-input\fR
.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_THREADS\fR
Same as \fB\-T, \-\-threads\fR
.TP
\fBSLURM_TIMELIMIT\fR
Same as \fB\-t, \-\-time\fR
.TP
\fBSLURM_UNBUFFEREDIO\fR
Same as \fB\-u, \-\-unbuffered\fR
.TP
\fBSLURM_WAIT\fR
Same as \fB\-W, \-\-wait\fR
.TP
\fBSLURM_WORKING_DIR\fR
\fB\-D, \-\-chdir\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
\fBBASIL_RESERVATION_ID\fR
The reservation ID on Cray systems running ALPS/BASIL only.

.TP
\fBSLURM_CHECKPOINT_IMAGE_DIR\fR
Directory into which checkpoint images should be written
if specified on the execute line.

.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 IDs or masks for this node>)

.TP
\fBSLURM_CPUS_ON_NODE\fR
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.
The select/cons_res plugin allocates individual processors 
to jobs, so this number indicates the number of processors 
on this node allocated to the job.

.TP
\fBSLURM_GTIDS\fR
Global task IDs running on this node.
Zero origin and comma separated.
.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_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_VERBOSE\fR
\-\-mem_bind verbosity (quiet,verbose).
.TP
\fBSLURM_MEM_BIND_TYPE\fR
\-\-mem_bind type (none,rank,map_mem:,mask_mem:)
.TP
\fBSLURM_MEM_BIND_LIST\fR
\-\-mem_bind map or mask list (<list of IDs or masks for this node>)

.TP
\fBSLURM_NNODES\fR
Total number of nodes in the job's resource allocation
.TP
\fBSLURM_NODEID\fR
The relative node ID of the current node
.TP
\fBSLURM_NODELIST\fR
List of nodes allocated to the job
.TP
\fBSLURM_NPROCS\fR
Total number of processes in the current 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_STEPID\fR
The step ID of the current job
.TP
\fBSLURM_TASK_PID\fR
The process ID of the task being started.
.TP
\fBSLURM_TASKS_PER_NODE\fR
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.
.TP
\fBSLURM_UMASK\fR
The umask (user file\-create mask) at the time of job submission.
This value is propagated to the spawned processes.
.TP
\fBMPIRUN_NOALLOCATE\fR
Do not allocate a block on Blue Gene systems only.
.TP
\fBMPIRUN_NOFREE\fR
Do not free a block on Blue Gene systems only.
.TP
\fBMPIRUN_PARTITION\fR
The block name on Blue Gene systems only.

.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
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 \fIhttps://computing.llnl.gov/linux/slurm/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, specify a rank of '*' (in which case you probably 
should not be using this option).
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.
.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
5: linux16.llnl.gov
6: linux17.llnl.gov
7: task:7

.fi


.SH "EXAMPLES"
This simple example demonstrates the execution of the command \fBhostname\fR
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)

.nf

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

.fi
.PP
The output of test.sh would be found in the default output file
"slurm\-42.out."
.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_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 follwing 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
  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]

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

.nf

> 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_NPROCS \-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
.PP
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.

.nf

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


.SH "COPYING"
Copyright (C) 2006\-2007 The Regents of the University of California.
Copyright (C) 2008\-2009 Lawrence Livermore National Security.
Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
CODE\-OCEC\-09\-009. All rights reserved.
.LP
This file is part of SLURM, a resource management program.
For details, see <https://computing.llnl.gov/linux/slurm/>.
.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), \fBsttach\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),