NAME¶salloc - Obtain a Slurm job allocation (a set of nodes), execute a command, and then release the allocation when the command is finished.
SYNOPSIS¶salloc [OPTIONS(0)...] [ : [OPTIONS(n)...]] script(0) [args(0)...]
Option(s) define multiple jobs in a co-scheduled heterogeneous
job. For more details about heterogeneous jobs see the document
DESCRIPTION¶salloc is used to allocate a Slurm job allocation, which is a set of resources (nodes), possibly with some set of constraints (e.g. number of processors per node). When salloc successfully obtains the requested allocation, it then runs the command specified by the user. Finally, when the user specified command is complete, salloc relinquishes the job allocation.
The command may be any program the user wishes. Some typical commands are xterm, a shell script containing srun commands, and srun (see the EXAMPLES section). If no command is specified, then the value of SallocDefaultCommand in slurm.conf is used. If SallocDefaultCommand is not set, then salloc runs the user's default shell.
The following document describes the influence of various options
on the allocation of cpus to jobs and tasks.
NOTE: The salloc logic includes support to save and restore the terminal line settings and is designed to be executed in the foreground. If you need to execute salloc in the background, set its standard input to some file, for example: "salloc -n16 a.out </dev/null &"
RETURN VALUE¶If salloc is unable to execute the user script, it will return 1 and print errors to stderr. Else if success or if killed by signals HUP, INT, KILL, or QUIT: it will return 0.
- -A, --account=<account>
- Charge resources used by this job to specified account. The account is an arbitrary string. The account name may be changed after job submission using the scontrol command.
- Define the job accounting and profiling sampling intervals. This can be used to override the JobAcctGatherFrequency parameter in Slurm's configuration file, slurm.conf. The supported format is as follows:
- where <datatype>=<interval> specifies the task sampling interval for the jobacct_gather plugin or a sampling interval for a profiling type by the acct_gather_profile plugin. Multiple, comma-separated <datatype>=<interval> intervals may be specified. Supported datatypes are as follows:
- where <interval> 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.
- where <interval> is the sampling interval in seconds for energy profiling using the acct_gather_energy plugin
- where <interval> is the sampling interval in seconds for infiniband profiling using the acct_gather_infiniband plugin.
- where <interval> is the sampling interval in seconds for filesystem profiling using the acct_gather_filesystem plugin.
The default value for the task sampling interval is 30. The default value for all other intervals is 0. An interval of 0 disables sampling of the specified type. If the task sampling interval is 0, accounting information is collected only at job termination (reducing Slurm interference with the job).
Smaller (non-zero) values have a greater impact upon job performance, but a value of 30 seconds is not likely to be noticeable for applications having less than 10,000 tasks.
- -B --extra-node-info=<sockets[:cores[:threads]]>
- Restrict node selection to nodes with at least the specified number of
sockets, cores per socket and/or threads per core. NOTE: These options do
not specify the resource allocation size. 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:
--sockets-per-node=<sockets> --cores-per-socket=<cores> --threads-per-core=<threads>If task/affinity plugin is enabled, then specifying an allocation in this manner also results in subsequently launched tasks being bound to threads if the -B option specifies a thread count, otherwise an option of cores if a core count is specified, otherwise an option of sockets. If SelectType is configured to select/cons_res, it must have a parameter of CR_Core, CR_Core_Memory, CR_Socket, or CR_Socket_Memory for this option to be honored. If not specified, the scontrol show job will display 'ReqS:C:T=*:*:*'. This option applies to job allocations.
- Burst buffer specification. The form of the specification is system dependent. Note the burst buffer may not be accessible from a login node, but require that salloc spawn a shell on one of it's allocated compute nodes. See the description of SallocDefaultCommand in the slurm.conf man page for more information about how to spawn a remote shell.
- Path of file containing burst buffer specification. The form of the specification is system dependent. Also see --bb. Note the burst buffer may not be accessible from a login node, but require that salloc spawn a shell on one of it's allocated compute nodes. See the description of SallocDefaultCommand in the slurm.conf man page for more information about how to spawn a remote shell.
- Submit the batch script to the Slurm controller immediately, like normal,
but tell the controller to defer the allocation of the job until the
Time may be of the form HH:MM:SS to run a job at a specific time of day (seconds are optional). (If that time is already past, the next day is assumed.) You may also specify midnight, noon, fika (3 PM) or teatime (4 PM) and you can have a time-of-day suffixed with AM or PM for running in the morning or the evening. You can also say what day the job will be run, by specifying a date of the form MMDDYY or MM/DD/YY YYYY-MM-DD. Combine date and time using the following format YYYY-MM-DD[THH:MM[:SS]]. You can also give times like now + count time-units, where the time-units can be seconds (default), minutes, hours, days, or weeks and you can tell Slurm to run the job today with the keyword today and to run the job tomorrow with the keyword tomorrow. The value may be changed after job submission using the scontrol command. For example:
--begin=16:00 --begin=now+1hour --begin=now+60 (seconds by default) --begin=2010-01-20T12:34:00
Notes on date/time specifications: - Although the 'seconds' field of the HH:MM:SS time specification is allowed by the code, note that the poll time of the Slurm scheduler is not precise enough to guarantee dispatch of the job on the exact second. The job will be eligible to start on the next poll following the specified time. The exact poll interval depends on the Slurm scheduler (e.g., 60 seconds with the default sched/builtin). - If no time (HH:MM:SS) is specified, the default is (00:00:00). - If a date is specified without a year (e.g., MM/DD) then the current year is assumed, unless the combination of MM/DD and HH:MM:SS has already passed for that year, in which case the next year is used.
- Force salloc to ring the terminal bell when the job allocation is granted (and only if stdout is a tty). By default, salloc only rings the bell if the allocation is pending for more than ten seconds (and only if stdout is a tty). Also see the option --no-bell.
- 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.
- An arbitrary comment.
- -C, --constraint=<list>
- Nodes can have features assigned to them by the Slurm administrator. Users can specify which of these features are required by their job using the constraint option. Only nodes having features matching the job constraints will be used to satisfy the request. Multiple constraints may be specified with AND, OR, matching OR, resource counts, etc. (some operators are not supported on all system types). Supported constraint options include:
- Single Name
- Only nodes which have the specified feature will be used. For example, --constraint="intel"
- Node Count
- A request can specify the number of nodes needed with some feature by appending an asterisk and count after the feature name. For example "--nodes=16 --constraint=graphics*4 ..." indicates that the job requires 16 nodes and that at least four of those nodes must have the feature "graphics."
- If only nodes with all of specified features will be used. The ampersand is used for an AND operator. For example, --constraint="intel&gpu"
- If only nodes with at least one of specified features will be used. The vertical bar is used for an OR operator. For example, --constraint="intel|amd"
- Matching OR
- If only one of a set of possible options should be used for all allocated nodes, then use the OR operator and enclose the options within square brackets. For example: "--constraint=[rack1|rack2|rack3|rack4]" might be used to specify that all nodes must be allocated on a single rack of the cluster, but any of those four racks can be used.
- Multiple Counts
- Specific counts of multiple resources may be specified by using the AND
operator and enclosing the options within square brackets. For example:
"--constraint=[rack1*2&rack2*4]" might be used to
specify that two nodes must be allocated from nodes with the feature of
"rack1" and four nodes must be allocated from nodes with the
NOTE: This construct does not support multiple Intel KNL NUMA or MCDRAM modes. For example, while "--constraint=[(knl&quad)*2&(knl&hemi)*4]" is not supported, "--constraint=[haswell*2&(knl&hemi)*4]" is supported. Specification of multiple KNL modes requires the use of a heterogeneous job.
- Parenthesis can be used to group like node features together. For example "--constraint=[(knl&snc4&flat)*4&haswell*1]" 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.
- If set, then the allocated nodes must form a contiguous set. Not honored with the topology/tree or topology/3d_torus plugins, both of which can modify the node ordering.
- Restrict node selection to nodes with at least the specified number of cores per socket. See additional information under -B option above when task/affinity plugin is enabled.
- --cpu-freq =<p1[-p2[:p3]]>
Request that job steps initiated by srun commands inside this allocation be run at some requested frequency if possible, on the CPUs selected for the step on the compute node(s).
p1 can be [#### | low | medium | high | highm1] which will set the frequency scaling_speed to the corresponding value, and set the frequency scaling_governor to UserSpace. See below for definition of the values.
p1 can be [Conservative | OnDemand | Performance | PowerSave] which will set the scaling_governor to the corresponding value. The governor has to be in the list set by the slurm.conf option CpuFreqGovernors.
When p2 is present, p1 will be the minimum scaling frequency and p2 will be the maximum scaling frequency.
p2 can be [#### | medium | high | highm1] p2 must be greater than p1.
p3 can be [Conservative | OnDemand | Performance | PowerSave | UserSpace] which will set the governor to the corresponding value.
If p3 is UserSpace, the frequency scaling_speed will be set by a power or energy aware scheduling strategy to a value between p1 and p2 that lets the job run within the site's power goal. The job may be delayed if p1 is higher than a frequency that allows the job to run within the goal.
If the current frequency is < min, it will be set to min. Likewise, if the current frequency is > max, it will be set to max.
Acceptable values at present include:
- frequency in kilohertz
- the lowest available frequency
- the highest available frequency
- (high minus one) will select the next highest available frequency
- attempts to set a frequency in the middle of the available range
- attempts to use the Conservative CPU governor
- attempts to use the OnDemand CPU governor (the default value)
- attempts to use the Performance CPU governor
- attempts to use the PowerSave CPU governor
- attempts to use the UserSpace CPU governor
The following informational environment variable is set in the job step when --cpu-freq option is requested.
This environment variable can also be used to supply the value for the CPU frequency request if it is set when the 'srun' command is issued. The --cpu-freq on the command line will override the environment variable value. The form on the environment variable is the same as the command line. See the ENVIRONMENT VARIABLES section for a description of the SLURM_CPU_FREQ_REQ variable.
NOTE: This parameter is treated as a request, not a requirement. If the job step's node does not support setting the CPU frequency, or the requested value is outside the bounds of the legal frequencies, an error is logged, but the job step is allowed to continue.
NOTE: Setting the frequency for just the CPUs of the job step implies that the tasks are confined to those CPUs. If task confinement (i.e., TaskPlugin=task/affinity or TaskPlugin=task/cgroup with the "ConstrainCores" option) is not configured, this parameter is ignored.
NOTE: When the step completes, the frequency and governor of each selected CPU is reset to the previous values.
NOTE: When submitting jobs with the --cpu-freq option with linuxproc as the ProctrackType can cause jobs to run too quickly before Accounting is able to poll for job information. As a result not all of accounting information will be present.
- -c, --cpus-per-task=<ncpus>
- Advise Slurm that ensuing job steps will require ncpus processors
per task. By default Slurm will allocate one processor per task.
For instance, consider an application that has 4 tasks, each requiring 3 processors. If our cluster is comprised of quad-processors nodes and we simply ask for 12 processors, the controller might give us only 3 nodes. However, by using the --cpus-per-task=3 options, the controller knows that each task requires 3 processors on the same node, and the controller will grant an allocation of 4 nodes, one for each of the 4 tasks.
- remove the job if no ending is possible before this deadline (start >
(deadline - time[-min])). Default is no deadline. Valid time formats are:
MMDD[YY] or MM/DD[/YY] or MM.DD[.YY]
- Do not reboot nodes in order to satisfied this job's feature specification if the job has been eligible to run for less than this time period. If the job has waited for less than the specified period, it will use only nodes which already have the specified features. The argument is in units of minutes. A default value may be set by a system administrator using the delay_boot option of the SchedulerParameters configuration parameter in the slurm.conf file, otherwise the default value is zero (no delay).
- -d, --dependency=<dependency_list>
- Defer the start of this job until the specified dependencies have been satisfied completed. <dependency_list> is of the form <type:job_id[:job_id][,type:job_id[:job_id]]> or <type:job_id[:job_id][?type:job_id[:job_id]]>. All dependencies must be satisfied if the "," separator is used. Any dependency may be satisfied if the "?" separator is used. 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. Once a job dependency fails due to the termination state of a preceding job, the dependent job will never be run, even if the preceding job is requeued and has a different termination state in a subsequent execution.
- This job can begin execution after the specified jobs have begun execution.
- This job can begin execution after the specified jobs have terminated.
- This job can begin execution after the specified jobs have terminated and any associated burst buffer stage out operations have completed.
- A task of this job array can begin execution after the corresponding task ID in the specified job has completed successfully (ran to completion with an exit code of zero).
- This job can begin execution after the specified jobs have terminated in some failed state (non-zero exit code, node failure, timed out, etc).
- This job can begin execution after the specified jobs have successfully executed (ran to completion with an exit code of zero).
- Resources allocated to this job should be used to expand the specified job. The job to expand must share the same QOS (Quality of Service) and partition. Gang scheduling of resources in the partition is also not supported.
- This job can begin execution after any previously launched jobs sharing the same job name and user have terminated. In other words, only one job by that name and owned by that user can be running or suspended at any point in time.
- -D, --chdir=<path>
- Change directory to path before beginning execution. The path can be specified as full path or relative path to the directory where the command is executed.
- The job allocation can not share nodes with other running jobs (or just other users with the "=user" option or with the "=mcs" option). The default shared/exclusive behavior depends on system configuration and the partition's OverSubscribe option takes precedence over the job's option.
- -F, --nodefile=<node file>
- Much like --nodelist, but the list is contained in a file of name node file. The node names of the list may also span multiple lines in the file. Duplicate node names in the file will be ignored. The order of the node names in the list is not important; the node names will be sorted by Slurm.
- This option will load login environment variables for the user specified in the --uid option. The environment variables are retrieved by running something of this sort "su - <username> -c /usr/bin/env" and parsing the output. Be aware that any environment variables already set in salloc's environment will take precedence over any environment variables in the user's login environment. The optional timeout value is in seconds. Default value is 3 seconds. The optional mode value control the "su" options. With a mode value of "S", "su" is executed without the "-" option. With a mode value of "L", "su" is executed with the "-" option, replicating the login environment. If mode not specified, the mode established at Slurm build time is used. Example of use include "--get-user-env", "--get-user-env=10" "--get-user-env=10L", and "--get-user-env=S". NOTE: This option only works if the caller has an effective uid of "root". This option was originally created for use by Moab.
- Submit the job with the specified group's group access permissions. group may be the group name or the numerical group ID. In the default Slurm configuration, this option is only valid when used by the user root.
- Specifies a comma delimited list of generic consumable resources. The format of each entry on the list is "name[[:type]:count]". The name is that of the consumable resource. The count is the number of those resources with a default value of 1. The specified resources will be allocated to the job on each node. The available generic consumable resources is configurable by the system administrator. A list of available generic consumable resources will be printed and the command will exit if the option argument is "help". Examples of use include "--gres=gpu:2,mic:1", "--gres=gpu:kepler:2", and "--gres=help".
- Specify generic resource task binding options.
- Disable filtering of CPUs with respect to generic resource locality. This option is currently required to use more CPUs than are bound to a GRES (i.e. if a GPU is bound to the CPUs on one socket, but resources on more than one socket are required to run the job). This option may permit a job to be allocated resources sooner than otherwise possible, but may result in lower job performance.
- The only CPUs available to the job will be those bound to the selected GRES (i.e. the CPUs identified in the gres.conf file will be strictly enforced). This option may result in delayed initiation of a job. For example a job requiring two GPUs and one CPU will be delayed until both GPUs on a single socket are available rather than using GPUs bound to separate sockets, however the application performance may be improved due to improved communication speed. Requires the node to be configured with more than one socket and resource filtering will be performed on a per-socket basis.
- -H, --hold
- Specify the job is to be submitted in a held state (priority of zero). A held job can now be released using scontrol to reset its priority (e.g. "scontrol release <job_id>").
- -h, --help
- Display help information and exit.
- Bind tasks according to application hints.
- Select settings for compute bound applications: use all cores in each socket, one thread per core.
- Select settings for memory bound applications: use only one core in each socket, one thread per core.
- [don't] use extra threads with in-core multi-threading which can benefit communication intensive applications. Only supported with the task/affinity plugin.
- show this help message
- -I, --immediate[=<seconds>]
- exit if resources are not available within the time period specified. If no argument is given, resources must be available immediately for the request to succeed. By default, --immediate is off, and the command will block until resources become available. Since this option's argument is optional, for proper parsing the single letter option must be followed immediately with the value and not include a space between them. For example "-I60" and not "-I 60".
- -J, --job-name=<jobname>
- Specify a name for the job allocation. The specified name will appear along with the job id number when querying running jobs on the system. The default job name is the name of the "command" specified on the command line.
- Allocate resources as the specified job id. NOTE: Only valid for users root and SlurmUser.
- -K, --kill-command[=signal]
- salloc always runs a user-specified command once the allocation is granted. salloc will wait indefinitely for that command to exit. If you specify the --kill-command option salloc will send a signal to your command any time that the Slurm controller tells salloc that its job allocation has been revoked. The job allocation can be revoked for a couple of reasons: someone used scancel to revoke the allocation, or the allocation reached its time limit. If you do not specify a signal name or number and Slurm is configured to signal the spawned command at job termination, the default signal is SIGHUP for interactive and SIGTERM for non-interactive sessions. Since this option's argument is optional, for proper parsing the single letter option must be followed immediately with the value and not include a space between them. For example "-K1" and not "-K 1".
- -k, --no-kill
- Do not automatically terminate a job if one of the nodes it has been
allocated fails. The user will assume the responsibilities for
fault-tolerance should a node fail. When there is a node failure, any
active job steps (usually MPI jobs) on that node will almost certainly
suffer a fatal error, but with --no-kill, the job allocation will not be
revoked so the user may launch new job steps on the remaining nodes in
By default Slurm terminates the entire job allocation if any node fails in its range of allocated nodes.
- -L, --licenses=<license>
- Specification of licenses (or other resources available on all nodes of the cluster) which must be allocated to this job. License names can be followed by a colon and count (the default count is one). Multiple license names should be comma separated (e.g. "--licenses=foo:4,bar").
- -M, --clusters=<string>
- Clusters to issue commands to. Multiple cluster names may be comma separated. The job will be submitted to the one cluster providing the earliest expected job initiation time. The default value is the current cluster. A value of 'all' will query to run on all clusters. Note that the SlurmDBD must be up for this option to work properly.
- -m, --distribution=
Specify alternate distribution methods for remote processes. In salloc, this only sets environment variables that will be used by subsequent srun requests. This option controls the assignment of tasks to the nodes on which resources have been allocated, and the distribution of those resources to tasks for binding (task affinity). The first distribution method (before the ":") controls the distribution of resources across nodes. The optional second distribution method (after the ":") controls the distribution of resources across sockets within a node. Note that with select/cons_res, the number of cpus allocated on each socket and node may be different. Refer to https://slurm.schedmd.com/mc_support.html for more information on resource allocation, assignment of tasks to nodes, and binding of tasks to CPUs.
First distribution method:
- The block distribution method will distribute tasks to a node such that consecutive tasks share a node. For example, consider an allocation of three nodes each with two cpus. A four-task block distribution request will distribute those tasks to the nodes with tasks one and two on the first node, task three on the second node, and task four on the third node. Block distribution is the default behavior if the number of tasks exceeds the number of allocated nodes.
- The cyclic distribution method will distribute tasks to a node such that consecutive tasks are distributed over consecutive nodes (in a round-robin fashion). For example, consider an allocation of three nodes each with two cpus. A four-task cyclic distribution request will distribute those tasks to the nodes with tasks one and four on the first node, task two on the second node, and task three on the third node. Note that when SelectType is select/cons_res, the same number of CPUs may not be allocated on each node. Task distribution will be round-robin among all the nodes with CPUs yet to be assigned to tasks. Cyclic distribution is the default behavior if the number of tasks is no larger than the number of allocated nodes.
- The tasks are distributed in blocks of a specified size. The options
include a number representing the size of the task block. This is followed
by an optional specification of the task distribution scheme within a
block of tasks and between the blocks of tasks. The number of tasks
distributed to each node is the same as for cyclic distribution, but the
taskids assigned to each node depend on the plane size. For more details
(including examples and diagrams), please see
- The arbitrary method of distribution will allocate processes in-order as
listed in file designated by the environment variable SLURM_HOSTFILE. If
this variable is listed it will over ride any other method specified. If
not set the method will default to block. Inside the hostfile must contain
at minimum the number of hosts requested and be one per line or comma
separated. If specifying a task count (-n,
--ntasks=<number>), your tasks will be laid out on the
nodes in the order of the file.
NOTE: The arbitrary distribution option on a job allocation only controls the nodes to be allocated to the job and not the allocation of CPUs on those nodes. This option is meant primarily to control a job step's task layout in an existing job allocation for the srun command.
- Second distribution method:
- The block distribution method will distribute tasks to sockets such that consecutive tasks share a socket.
- The cyclic distribution method will distribute tasks to sockets such that consecutive tasks are distributed over consecutive sockets (in a round-robin fashion). Tasks requiring more than one CPU will have all of those CPUs allocated on a single socket if possible.
- The fcyclic distribution method will distribute tasks to sockets such that consecutive tasks are distributed over consecutive sockets (in a round-robin fashion). Tasks requiring more than one CPU will have each CPUs allocated in a cyclic fashion across sockets.
- Notify user by email when certain event types occur. Valid type values are NONE, BEGIN, END, FAIL, REQUEUE, ALL (equivalent to BEGIN, END, FAIL, REQUEUE, and STAGE_OUT), STAGE_OUT (burst buffer stage out and teardown completed), TIME_LIMIT, TIME_LIMIT_90 (reached 90 percent of time limit), TIME_LIMIT_80 (reached 80 percent of time limit), and TIME_LIMIT_50 (reached 50 percent of time limit). Multiple type values may be specified in a comma separated list. The user to be notified is indicated with --mail-user.
- User to receive email notification of state changes as defined by --mail-type. The default value is the submitting user.
- Used only when the mcs/group plugin is enabled. This parameter is a group among the groups of the user. Default value is calculated by the Plugin mcs if it's enabled.
- Specify the real memory required per node. Default units are megabytes
unless the SchedulerParameters configuration parameter includes the
"default_gbytes" option for gigabytes. Different units can be
specified using the suffix [K|M|G|T]. Default value is
DefMemPerNode and the maximum value is MaxMemPerNode. If
configured, both of parameters can be seen using the scontrol show
config command. This parameter would generally be used if whole nodes
are allocated to jobs (SelectType=select/linear). Also see
--mem-per-cpu. The --mem and --mem-per-cpu options
are mutually exclusive.
NOTE: A memory size specification of zero is treated as a special case and grants the job access to all of the memory on each node. If the job is allocated multiple nodes in a heterogeneous cluster, the memory limit on each node will be that of the node in the allocation with the smallest memory size (same limit will apply to every node in the job's allocation).
NOTE: Enforcement of memory limits currently relies upon the task/cgroup plugin or enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected). In both cases memory use is based upon the job's Resident Set Size (RSS). A task may exceed the memory limit until the next periodic accounting sample.
- Minimum memory required per allocated CPU. Default units are megabytes unless the SchedulerParameters configuration parameter includes the "default_gbytes" option for gigabytes. Different units can be specified using the suffix [K|M|G|T]. Default value is DefMemPerCPU and the maximum value is MaxMemPerCPU (see exception below). If configured, both of parameters can be seen using the scontrol show config command. Note that if the job's --mem-per-cpu value exceeds the configured MaxMemPerCPU, then the user's limit will be treated as a memory limit per task; --mem-per-cpu will be reduced to a value no larger than MaxMemPerCPU; --cpus-per-task will be set and the value of --cpus-per-task multiplied by the new --mem-per-cpu value will equal the original --mem-per-cpu value specified by the user. This parameter would generally be used if individual processors are allocated to jobs (SelectType=select/cons_res). If resources are allocated by the core, socket or whole nodes; the number of CPUs allocated to a job may be higher than the task count and the value of --mem-per-cpu should be adjusted accordingly. Also see --mem. --mem and --mem-per-cpu are mutually exclusive.
- Bind tasks to memory. Used only when the task/affinity plugin is enabled
and the NUMA memory functions are available. Note that the resolution
of CPU and memory binding may differ on some architectures. For
example, CPU binding may be performed at the level of the cores within a
processor while memory binding will be performed at the level of nodes,
where the definition of "nodes" may differ from system to
system. By default no memory binding is performed; any task using any CPU
can use any memory. This option is typically used to ensure that each task
is bound to the memory closest to it's assigned CPU. The use of any
type other than "none" or "local" is not
recommended. If you want greater control, try running a simple test
code with the options "--cpu-bind=verbose,none
--mem-bind=verbose,none" to determine the specific configuration.
NOTE: To have Slurm always report on the selected memory binding for all commands executed in a shell, you can enable verbose mode by setting the SLURM_MEM_BIND environment variable value to "verbose".
The following informational environment variables are set when --mem-bind is in use:
SLURM_MEM_BIND_LIST SLURM_MEM_BIND_PREFER SLURM_MEM_BIND_SORT SLURM_MEM_BIND_TYPE SLURM_MEM_BIND_VERBOSE
See the ENVIRONMENT VARIABLES section for a more detailed description of the individual SLURM_MEM_BIND* variables.
Supported options include:
- show this help message
- Use memory local to the processor in use
- Bind by setting memory masks on tasks (or ranks) as specified where <list> is <numa_id_for_task_0>,<numa_id_for_task_1>,... The mapping is specified for a node and identical mapping is applied to the tasks on every node (i.e. the lowest task ID on each node is mapped to the first ID specified in the list, etc.). NUMA IDs are interpreted as decimal values unless they are preceded with '0x' in which case they interpreted as hexadecimal values. If the number of tasks (or ranks) exceeds the number of elements in this list, elements in the list will be reused as needed starting from the beginning of the list. To simplify support for large task counts, the lists may follow a map with an asterisk and repetition count For example "map_mem:0x0f*4,0xf0*4". Not supported unless the entire node is allocated to the job.
- Bind by setting memory masks on tasks (or ranks) as specified where <list> is <numa_mask_for_task_0>,<numa_mask_for_task_1>,... The mapping is specified for a node and identical mapping is applied to the tasks on every node (i.e. the lowest task ID on each node is mapped to the first mask specified in the list, etc.). NUMA masks are always interpreted as hexadecimal values. Note that masks must be preceded with a '0x' if they don't begin with [0-9] so they are seen as numerical values. If the number of tasks (or ranks) exceeds the number of elements in this list, elements in the list will be reused as needed starting from the beginning of the list. To simplify support for large task counts, the lists may follow a mask with an asterisk and repetition count For example "mask_mem:0*4,1*4". Not supported unless the entire node is allocated to the job.
- don't bind tasks to memory (default)
- Prefer use of first specified NUMA node, but permit use of other available NUMA nodes.
- quietly bind before task runs (default)
- bind by task rank (not recommended)
- sort free cache pages (run zonesort on Intel KNL nodes)
- verbosely report binding before task runs
- Specify a minimum number of logical cpus/processors per node.
- -N, --nodes=<minnodes[-maxnodes]>
- Request that a minimum of minnodes nodes be allocated to this job. A maximum node count may also be specified with maxnodes. If only one number is specified, this is used as both the minimum and maximum node count. The partition's node limits supersede those of the job. If a job's node limits are outside of the range permitted for its associated partition, the job will be left in a PENDING state. This permits possible execution at a later time, when the partition limit is changed. If a job node limit exceeds the number of nodes configured in the partition, the job will be rejected. Note that the environment variable SLURM_JOB_NODES will be set to the count of nodes actually allocated to the job. See the ENVIRONMENT VARIABLES section for more information. If -N is not specified, the default behavior is to allocate enough nodes to satisfy the requirements of the -n and -c options. The job will be allocated as many nodes as possible within the range specified and without delaying the initiation of the job. The node count specification may include a numeric value followed by a suffix of "k" (multiplies numeric value by 1,024) or "m" (multiplies numeric value by 1,048,576).
- -n, --ntasks=<number>
- salloc does not launch tasks, it requests an allocation of resources and executed some command. This option advises the Slurm controller that job steps run within this allocation will launch a maximum of number tasks and sufficient resources are allocated to accomplish this. The default is one task per node, but note that the --cpus-per-task option will change this default.
- Specify information pertaining to the switch or network. The interpretation of type is system dependent. This option is supported when running Slurm on a Cray natively. It is used to request using Network Performance Counters. Only one value per request is valid. All options are case in-sensitive. In this configuration supported values include:
- Use the system-wide network performance counters. Only nodes requested will be marked in use for the job allocation. If the job does not fill up the entire system the rest of the nodes are not able to be used by other jobs using NPC, if idle their state will appear as PerfCnts. These nodes are still available for other jobs not using NPC.
- Use the blade network performance counters. Only nodes requested will be marked in use for the job allocation. If the job does not fill up the entire blade(s) allocated to the job those blade(s) are not able to be used by other jobs using NPC, if idle their state will appear as PerfCnts. These nodes are still available for other jobs not using NPC.
In all cases the job allocation request must specify the --exclusive option. Otherwise the request will be denied.
Also with any of these options steps are not allowed to share blades, so resources would remain idle inside an allocation if the step running on a blade does not take up all the nodes on the blade.
The network option is also supported on systems with IBM's Parallel Environment (PE). See IBM's LoadLeveler job command keyword documentation about the keyword "network" for more information. Multiple values may be specified in a comma separated list. All options are case in-sensitive. Supported values include:
- Enable bulk transfer of data using Remote Direct-Memory Access (RDMA). The optional resources specification is a numeric value which can have a suffix of "k", "K", "m", "M", "g" or "G" for kilobytes, megabytes or gigabytes. NOTE: The resources specification is not supported by the underlying IBM infrastructure as of Parallel Environment version 2.2 and no value should be specified at this time.
- Number of Collectve Acceleration Units (CAU) required. Applies only to IBM Power7-IH processors. Default value is zero. Independent CAU will be allocated for each programming interface (MPI, LAPI, etc.)
- Specify the device name to use for communications (e.g. "eth0" or "mlx4_0").
- Specify the device type to use for communications. The supported values of type are: "IB" (InfiniBand), "HFI" (P7 Host Fabric Interface), "IPONLY" (IP-Only interfaces), "HPCE" (HPC Ethernet), and "KMUX" (Kernel Emulation of HPCE). The devices allocated to a job must all be of the same type. The default value depends upon depends upon what hardware is available and in order of preferences is IPONLY (which is not considered in User Space mode), HFI, IB, HPCE, and KMUX.
- IMMED =<count>
- Number of immediate send slots per window required. Applies only to IBM Power7-IH processors. Default value is zero.
- INSTANCES =<count>
- Specify number of network connections for each task on each network connection. The default instance count is 1.
- Use Internet Protocol (IP) version 4 communications (default).
- Use Internet Protocol (IP) version 6 communications.
- Use the LAPI programming interface.
- Use the MPI programming interface. MPI is the default interface.
- Use the PAMI programming interface.
- Use the OpenSHMEM programming interface.
- Use all available switch networks (default).
- Use one available switch network.
- Use the UPC programming interface.
- Use User Space communications.
- Some examples of network specifications:
- Create two user space connections for MPI communications on every switch network for each task.
- Create three user space connections for MPI communications on every InfiniBand network for each task.
- Create a IP version 4 connection for LAPI communications on one switch network for each task.
- Create two user space connections each for LAPI and MPI communications on every switch network for each task. Note that SN_ALL is the default option so every switch network is used. Also note that Instances=2 specifies that two connections are established for each protocol (LAPI and MPI) and each task. If there are two networks and four tasks on the node then a total of 32 connections are established (2 instances x 2 protocols x 2 networks x 4 tasks).
- Run the job with an adjusted scheduling priority within Slurm. With no adjustment value the scheduling priority is decreased by 100. A negative nice value increases the priority, otherwise decreases it. The adjustment range is +/- 2147483645. Only privileged users can specify a negative adjustment.
- Request the maximum ntasks be invoked on each core. Meant to be used with the --ntasks option. Related to --ntasks-per-node except at the core level instead of the node level. NOTE: This option is not supported unless SelectType=cons_res is configured (either directly or indirectly on Cray systems) along with the node's core count.
- Request that ntasks be invoked on each node. If used with the --ntasks option, the --ntasks option will take precedence and the --ntasks-per-node will be treated as a maximum count of tasks per node. Meant to be used with the --nodes option. This is related to --cpus-per-task=ncpus, but does not require knowledge of the actual number of cpus on each node. In some cases, it is more convenient to be able to request that no more than a specific number of tasks be invoked on each node. Examples of this include submitting a hybrid MPI/OpenMP app where only one MPI "task/rank" should be assigned to each node while allowing the OpenMP portion to utilize all of the parallelism present in the node, or submitting a single setup/cleanup/monitoring job to each node of a pre-existing allocation as one step in a larger job script.
- Request the maximum ntasks be invoked on each socket. Meant to be used with the --ntasks option. Related to --ntasks-per-node except at the socket level instead of the node level. NOTE: This option is not supported unless SelectType=cons_res is configured (either directly or indirectly on Cray systems) along with the node's socket count.
- Silence salloc's use of the terminal bell. Also see the option --bell.
- immediately exit after allocating resources, without running a command. However, the Slurm job will still be created and will remain active and will own the allocated resources as long as it is active. You will have a Slurm job id with no associated processes or tasks. You can submit srun commands against this resource allocation, if you specify the --jobid= option with the job id of this Slurm job. Or, this can be used to temporarily reserve a set of resources so that other jobs cannot use them for some period of time. (Note that the Slurm job is subject to the normal constraints on jobs, including time limits, so that eventually the job will terminate and the resources will be freed, or you can terminate the job manually using the scancel command.)
- -O, --overcommit
- Overcommit resources. When applied to job allocation, only one CPU is allocated to the job per node and options used to specify the number of tasks per node, socket, core, etc. are ignored. When applied to job step allocations (the srun command when executed within an existing job allocation), this option can be used to launch more than one task per CPU. Normally, srun will not allocate more than one process per CPU. By specifying --overcommit you are explicitly allowing more than one process per CPU. However no more than MAX_TASKS_PER_NODE tasks are permitted to execute per node. NOTE: MAX_TASKS_PER_NODE is defined in the file slurm.h and is not a variable, it is set at Slurm build time.
- -p, --partition=<partition_names>
- Request a specific partition for the resource allocation. If not specified, the default behavior is to allow the slurm controller to select the default partition as designated by the system administrator. If the job can use more than one partition, specify their names in a comma separate list and the one offering earliest initiation will be used with no regard given to the partition name ordering (although higher priority partitions will be considered first). When the job is initiated, the name of the partition used will be placed first in the job record partition string.
- Comma separated list of power management plugin options. Currently available flags include: level (all nodes allocated to the job should have identical power caps, may be disabled by the Slurm configuration option PowerParameters=job_no_level).
- Request a specific job priority. May be subject to configuration specific constraints. value should either be a numeric value or "TOP" (for highest possible value). Only Slurm operators and administrators can set the priority of a job.
- enables detailed data collection by the acct_gather_profile plugin. Detailed data are typically time-series that are stored in an HDF5 file for the job or an InfluxDB database depending on the configured plugin.
- All data types are collected. (Cannot be combined with other values.)
- No data types are collected. This is the default. (Cannot be combined with other values.)
- Energy data is collected.
- Task (I/O, Memory, ...) data is collected.
- Lustre data is collected.
- Network (InfiniBand) data is collected.
- -q, --qos=<qos>
- Request a quality of service for the job. QOS values can be defined for each user/cluster/account association in the Slurm database. Users will be limited to their association's defined set of qos's when the Slurm configuration parameter, AccountingStorageEnforce, includes "qos" in it's definition.
- -Q, --quiet
- Suppress informational messages from salloc. Errors will still be displayed.
- Force the allocated nodes to reboot before starting the job. This is only supported with some system configurations and will otherwise be silently ignored.
- Allocate resources for the job from the named reservation.
--share The --share option has been replaced by the --oversubscribe option described below.
- -s, --oversubscribe
- The job allocation can over-subscribe resources with other running jobs. The resources to be over-subscribed can be nodes, sockets, cores, and/or hyperthreads depending upon configuration. The default over-subscribe behavior depends on system configuration and the partition's OverSubscribe option takes precedence over the job's option. This option may result in the allocation being granted sooner than if the --oversubscribe option was not set and allow higher system utilization, but application performance will likely suffer due to competition for resources. Also see the --exclusive option.
- -S, --core-spec=<num>
- Count of specialized cores per node reserved by the job for system operations and not used by the application. The application will not use these cores, but will be charged for their allocation. Default value is dependent upon the node's configured CoreSpecCount value. If a value of zero is designated and the Slurm configuration option AllowSpecResourcesUsage is enabled, the job will be allowed to override CoreSpecCount and use the specialized resources on nodes it is allocated. This option can not be used with the --thread-spec option.
- When a job is within sig_time seconds of its end time, send it the signal sig_num. Due to the resolution of event handling by Slurm, the signal may be sent up to 60 seconds earlier than specified. sig_num may either be a signal number or name (e.g. "10" or "USR1"). sig_time must have an integer value between 0 and 65535. By default, no signal is sent before the job's end time. If a sig_num is specified without any sig_time, the default time will be 60 seconds.
- Restrict node selection to nodes with at least the specified number of sockets. See additional information under -B option above when task/affinity plugin is enabled.
- Spread the job allocation over as many nodes as possible and attempt to evenly distribute tasks across the allocated nodes. This option disables the topology/tree plugin.
- When a tree topology is used, this defines the maximum count of switches desired for the job allocation and optionally the maximum time to wait for that number of switches. If Slurm finds an allocation containing more switches than the count specified, the job remains pending until it either finds an allocation with desired switch count or the time limit expires. It there is no switch count limit, there is no delay in starting the job. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds". The job's maximum time delay may be limited by the system administrator using the SchedulerParameters configuration parameter with the max_switch_wait parameter option. On a dragonfly network the only switch count supported is 1 since communication performance will be highest when a job is allocate resources on one leaf switch or more than 2 leaf switches. The default max-time is the max_switch_wait SchedulerParameters.
- -t, --time=<time>
- Set a limit on the total run time of the job allocation. 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 default time limit. When the time limit is reached, each task
in each job step is sent SIGTERM followed by SIGKILL. The interval between
signals is specified by the Slurm configuration parameter KillWait.
The OverTimeLimit configuration parameter may permit the job to run
longer than scheduled. Time resolution is one minute and second values are
rounded up to the next minute.
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".
- Count of specialized threads per node reserved by the job for system operations and not used by the application. The application will not use these threads, but will be charged for their allocation. This option can not be used with the --core-spec option.
- Restrict node selection to nodes with at least the specified number of threads per core. NOTE: "Threads" refers to the number of processing units on each core rather than the number of application tasks to be launched per core. See additional information under -B option above when task/affinity plugin is enabled.
- Set a minimum time limit on the job allocation. If specified, the job may have it's --time limit lowered to a value no lower than --time-min if doing so permits the job to begin execution earlier than otherwise possible. The job's time limit will not be changed after the job is allocated resources. This is performed by a backfill scheduling algorithm to allocate resources otherwise reserved for higher priority jobs. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds".
- Specify a minimum amount of temporary disk space per node. Default units are megabytes unless the SchedulerParameters configuration parameter includes the "default_gbytes" option for gigabytes. Different units can be specified using the suffix [K|M|G|T].
- -u, --usage
- Display brief help message and exit.
- Attempt to submit and/or run a job as user instead of the invoking user id. The invoking user's credentials will be used to check access permissions for the target partition. This option is only valid for user root. This option may be used by user root may use this option to run jobs as a normal user in a RootOnly partition for example. If run as root, salloc will drop its permissions to the uid specified after node allocation is successful. user may be the user name or numerical user ID.
- If a range of node counts is given, prefer the smaller count.
- -V, --version
- Display version information and exit.
- -v, --verbose
- Increase the verbosity of salloc's informational messages. Multiple -v's will further increase salloc's verbosity. By default only errors will be displayed.
- -w, --nodelist=<node name list>
- Request a specific list of hosts. The job will contain all of these hosts and possibly additional hosts as needed to satisfy resource requirements. 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 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. Duplicate node names in the list will be ignored. The order of the node names in the list is not important; the node names will be sorted by Slurm.
- Controls when the execution of the command begins with respect to when nodes are ready for use (i.e. booted). By default, the salloc command will return as soon as the allocation is made. This default can be altered using the salloc_wait_nodes option to the SchedulerParameters parameter in the slurm.conf file.
- Begin execution as soon as allocation can be made. Do not wait for all nodes to be ready for use (i.e. booted).
- Do not begin execution until all nodes are ready for use.
- Specify wckey to be used with job. If TrackWCKey=no (default) in the slurm.conf this value is ignored.
- -x, --exclude=<node name list>
- Explicitly exclude certain nodes from the resources granted to the job.
- 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 all.
INPUT ENVIRONMENT VARIABLES¶Upon startup, salloc will read and handle the options set in the following environment variables. Note: Command line options always override environment variables settings.
- Same as -A, --account
- Same as --acctg-freq
- Same as --bell
- Same as --bb
- SALLOC_CLUSTERS or SLURM_CLUSTERS
- Same as --clusters
- Same as -C, --constraint
- Same as --core-spec
- Same as -v, --verbose
- Same as --delay-boot
- Same as --exclusive
- Same as --gres-flags
- SALLOC_HINT or SLURM_HINT
- Same as --hint
- Same as -I, --immediate
- Same as --jobid
- Same as -K, --kill-command
- Same as --mem-bind
- Same as --network
- Same as --no-bell
- Same as -O, --overcommit
- Same as -p, --partition
- Same as --power
- Same as --profile
- Same as --qos
- When a tree topology is used, this defines the maximum count of switches desired for the job allocation and optionally the maximum time to wait for that number of switches. See --switches.
- Same as --reservation
- Same as --signal
- Same as --spread-job
- Same as --thread-spec
- Same as -t, --time
- Same as --use-min-nodes
- Same as --wait-all-nodes
- Same as --wckey
- Max time waiting for requested switches. See --switches
- The location of the Slurm configuration file.
- Specifies the exit code generated when a Slurm error occurs (e.g. invalid options). This can be used by a script to distinguish application exit codes from various Slurm error conditions. Also see SLURM_EXIT_IMMEDIATE.
- Specifies the exit code generated when the --immediate option is used and resources are not currently available. This can be used by a script to distinguish application exit codes from various Slurm error conditions. Also see SLURM_EXIT_ERROR.
OUTPUT ENVIRONMENT VARIABLES¶salloc will set the following environment variables in the environment of the executed program:
- The reservation ID on Cray systems running ALPS/BASIL only.
- For a heterogenous job allocation, the environment variables are set separately for each component.
- Name of the cluster on which the job is executing.
- Number of CPUs requested per task. Only set if the --cpus-per-task option is specified.
- Only set if the -m, --distribution option is specified.
- Account name associated of the job allocation.
- SLURM_JOB_ID (and SLURM_JOBID for backwards compatibility)
- The ID of the job allocation.
- 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 each node. The select/cons_res plugin allocates individual processors to jobs, so this number indicates the number of processors on each node allocated to the job allocation.
- SLURM_JOB_NODELIST (and SLURM_NODELIST for backwards compatibility)
- List of nodes allocated to the job.
- SLURM_JOB_NUM_NODES (and SLURM_NNODES for backwards compatibility)
- Total number of nodes in the job allocation.
- Name of the partition in which the job is running.
- Quality Of Service (QOS) of the job allocation.
- Advanced reservation containing the job allocation, if any.
- Set to value of the --mem-bind option.
- Set to bit mask used for memory binding.
- Set to "prefer" if the --mem-bind option includes the prefer option.
- Sort free cache pages (run zonesort on Intel KNL nodes)
- Set to the memory binding type specified with the --mem-bind option. Possible values are "none", "rank", "map_map", "mask_mem" and "local".
- Set to "verbose" if the --mem-bind option includes the verbose option. Set to "quiet" otherwise.
- Same as --mem-per-cpu
- Same as --mem
- Set to count of components in heterogeneous job.
- The directory from which salloc was invoked.
- The hostname of the computer from which salloc was invoked.
- Sets of node name, communication address and hostname for nodes allocated to the job from the cloud. Each element in the set if colon separated and each set is comma separated. For example: SLURM_NODE_ALIASES=ec0:126.96.36.199:foo,ec1:188.8.131.52:bar
- Same as -n, --ntasks
- Set to value of the --ntasks-per-core option, if specified.
- Set to value of the --ntasks-per-node option, if specified.
- Set to value of the --ntasks-per-socket option, if specified.
- Same as --profile
- Number of tasks to be initiated on each node. Values are comma separated and in the same order as SLURM_JOB_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.
SIGNALS¶While salloc is waiting for a PENDING job allocation, most signals will cause salloc to revoke the allocation request and exit.
However if the allocation has been granted and salloc has already started the specified command, then salloc will ignore most signals. salloc will not exit or release the allocation until the command exits. One notable exception is SIGHUP. A SIGHUP signal will cause salloc to release the allocation and exit without waiting for the command to finish. Another exception is SIGTERM, which will be forwarded to the spawned process.
EXAMPLES¶To get an allocation, and open a new xterm in which srun commands may be typed interactively:
- $ salloc -N16 xterm
salloc: Granted job allocation 65537
(at this point the xterm appears, and salloc waits for xterm to exit)
salloc: Relinquishing job allocation 65537
To grab an allocation of nodes and launch a parallel application on one command line (See the salloc man page for more examples):
- salloc -N5 srun -n10 myprogram
+To create a heterogeneous job with 3 components, each allocating a unique set of nodes:
- salloc -w node[2-3] : -w node4 : -w node[5-7] bash
salloc: job 32294 queued and waiting for resources
salloc: job 32294 has been allocated resources
salloc: Granted job allocation 32294
COPYING¶Copyright (C) 2006-2007 The Regents of the University of California. Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
Copyright (C) 2008-2010 Lawrence Livermore National Security.
Copyright (C) 2010-2018 SchedMD LLC.
This file is part of Slurm, a resource management program. For details, see <https://slurm.schedmd.com/>.
Slurm is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
Slurm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
SEE ALSO¶sinfo(1), sattach(1), sbatch(1), squeue(1), scancel(1), scontrol(1), slurm.conf(5), sched_setaffinity (2), numa (3)
|Slurm Commands||November 2018|