gres.conf(5)

NAME
gres.conf - Slurm configuration file for Generic RESource (GRES) management.

DESCRIPTION
gres.conf is an ASCII file which describes the configuration of Generic RESource (GRES) on each compute node. If the GRES information in the slurm.conf file does not fully describe those resources, then a gres.conf file should be included on each compute node. The file location can be modified at system build time using the DEFAULT_SLURM_CONF parameter or at execution time by setting the SLURM_CONF environment variable. The file will always be located in the same directory as the slurm.conf file.

If the GRES information in the slurm.conf file fully describes those resources (i.e. no "Cores", "File" or "Links" specification is required for that GRES type or that information is automatically detected), that information may be omitted from the gres.conf file and only the configuration information in the slurm.conf file will be used. The gres.conf file may be omitted completely if the configuration information in the slurm.conf file fully describes all GRES.

Parameter names are case insensitive. Any text following a "#" in the configuration file is treated as a comment through the end of that line. Changes to the configuration file take effect upon restart of Slurm daemons, daemon receipt of the SIGHUP signal, or execution of the command "scontrol reconfigure" unless otherwise noted.

CUDA Multi-Process Service (MPS) provides a mechanism where GPUs can be shared by multiple jobs, where each job is allocated some percentage of the GPU's resources. GPUs to be made available for MPS must be identified in the slurm.conf and gres.conf configuration files with each device File being explicitly named and its Count specified (typically a multiple of 100). If the GPU sharing that File name contains Core or Type parameters, that information will be automatically copied to the corresponding MPS GRES (details about those configuration parameters below). Note that the same GPU can be allocated either as a GPU type GRES or as an MPS type GRES, but not both. In other words, once a GPU has been allocated as a gres/gpu resource it will not be available as a gres/mps. Likewise, once a GPU has been allocated as a gres/mps resource it will not be available as a gres/gpu.

NOTE: Slurm support for gres/mps requires the use of the select/cons_tres plugin.

For more information on GRES scheduling, see https://slurm.schedmd.com/gres.html.

The overall configuration parameters available include:

AutoDetect
    Comma separated list of the types of GRES to auto detect. Valid options are 'nvml'. This is needed to use any outside system to configure GRES.

Count
    Number of resources of this type available on this node. The default value is set to the number of File values specified (if any), otherwise the default value is one. A suffix of "K", "M", "G", "T" or "P" may be used to multiply the number by 1024, 1048576, 1073741824, etc. respectively. For example: "Count=10G".

Cores
    Optionally specify the first thread CPU index numbers for the specific cores which can use this resource. For example, it may be strongly preferable to use specific cores with specific GRES devices (e.g. on a NUMA architecture). While Slurm can track and assign resources at the CPU or thread level, its scheduling algorithms used to co-allocate GRES devices with CPUs operates at a socket or NUMA level. Therefore it is not possible to preferentially assign GRES with different specific CPUs on the same NUMA or socket and this option should be used to identify all cores on some socket. Multiple cores may be specified using a comma delimited list or a range may be specified using a "-" separator (e.g. "0,1,2,3" or "0-3"). If a job specifies --gres-flags=enforce-binding, then only the identified cores can be allocated with each generic resource. This will tend to improve performance of jobs, but delay the allocation of resources to them. If specified and a job is not submitted with the --gres-flags=enforce-binding option the identified cores will be preferred for scheduled with each generic resource. If --gres-flags=disable-binding is specified, then any core can be used with the resources, which also increases the speed of Slurm's scheduling algorithm but can degrade the application performance. The --gres-flags=disable-binding 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). If any core can be effectively used with the resources, then do not specify the cores option for improved speed in the Slurm scheduling logic. A restart of the slurmctld is needed for changes to the Cores option to take affect. NOTE: If your cores contain multiple threads only the first thread (processing unit) of each core needs to be listed. Also note that since Slurm must be able to perform resource management on heterogeneous clusters having various processing unit numbering schemes, a logical processing unit index must be specified instead of the physical processing unit index. That processing unit logical index might not correspond to your physical index number. Processing unit 0 will be the first socket, first core and (if configured) first thread. If hyperthreading is enabled, processing unit 1 will always be the first socket, first core and second thread. If hyperthreading is not enabled, processing unit 1 will always be the first socket and second core. This numbering coincides with the processing unit logical number (PU L#) seen in "lstopo -l" command output.

File
    Fully qualified pathname of the device files associated with a resource. The name can include a numeric range suffix to be interpreted by Slurm (e.g. File=/dev/nvidia[0-3]). This field is generally required if enforcement of generic resource allocations is to be supported (i.e. prevents users from making use of resources allocated to a different user). Enforcement of the file allocation relies upon Linux Control Groups (cgroups) and Slurm's task/cgroup plugin, which will place the allocated files into the job's cgroup and prevent use of other files. Please see Slurm's Cgroups Guide for more information: https://slurm.schedmd.com/cgroups.html. If File is specified then Count must be either set to the number of file names specified or not set (the default value is the number of files specified). The exception to this is MPS. For MPS, each GPU would be identified by device file using the File parameter and Count would specify the number of MPS entries that would correspond to that GPU (typically 100 or some multiple of 100). NOTE: If you specify the File parameter for a resource on some node, the option must be specified on all nodes and Slurm will track the assignment of each specific resource on each node. Otherwise Slurm will only track a count of allocated resources rather than the state of each individual device file. NOTE: Drain a node before changing the count of records with File parameters (i.e. if you want to add or remove GPUs from a node's configuration). Failure to do so will result in any job using those GRES being aborted.

Links
    A comma-delimited list of numbers identifying the number of connections between this device and other devices to allow coscheduling of better connected devices. This is an ordered list in which the number of connections this specific device has to device number 0 would be in the first position, the number of connections it has to device number 1 in the second position, etc. A -1 indicates the device itself and a 0 indicates no connection. If specified, then this line can only contain a single GRES device (i.e. can only contain a single file via File). This is an optional value and is usually automatically determined if AutoDetect is enabled. A typical use case would be to identify GPUs having NVLink connectivity. Note that for GPUs, the minor number assigned by the OS and used in the device file (i.e. the X in /dev/nvidiaX) is not necessarily the same as the device number/index. The device number is created by sorting the GPUs by PCI bus ID and then numbering them starting from the smallest bus ID.

Name
    Name of the generic resource. Any desired name may be used. The name must match a value in GresTypes in slurm.conf. Each generic resource has an optional plugin which can provide resource-specific functionality. Generic resources that currently include an optional plugin are:

    gpu Graphics Processing Unit

    mps CUDA Multi-Process Service (MPS)

    nic Network Interface Card

    mic Intel Many Integrated Core (MIC) processor

NodeName
    An optional NodeName specification can be used to permit one gres.conf file to be used for all compute nodes in a cluster by specifying the node(s) that each line should apply to. The NodeName specification can use a Slurm hostlist specification as shown in the example below.

Type
    An optional arbitrary string identifying the type of device. For example, this might be used to identify a specific model of GPU, which users can then specify in a job request. If Type is specified, then Count is limited in size (currently 1024).

EXAMPLES

##################################################################
# Slurm's Generic Resource (GRES) configuration file
# Define GPU devices with MPS support
##################################################################
AutoDetect=nvml
Name=gpu Type=gtx560 File=/dev/nvidia0 COREs=0,1
Name=gpu Type=tesla File=/dev/nvidia1 COREs=2,3
Name=mps Count=100 File=/dev/nvidia0 COREs=0,1
Name=mps Count=100 File=/dev/nvidia1 COREs=2,3

##################################################################
# Slurm's Generic Resource (GRES) configuration file
# Overwrite system defaults and explicitly configure three GPUs
##################################################################
Name=gpu Type=tesla File=/dev/nvidia[0-1] COREs=0,1
# Name=gpu Type=tesla File=/dev/nvidia[2-3] COREs=2,3
# NOTE: nvidia2 device is out of service
Name=gpu Type=tesla File=/dev/nvidia3 COREs=2,3

##################################################################
# Slurm's Generic Resource (GRES) configuration file
# Use a single gres.conf file for all compute nodes - positive method
##################################################################
## Explicitly specify devices on nodes tux0-tux15
# NodeName=tux[0-15] Name=gpu File=/dev/nvidia[0-3]
# NOTE: tux3 nvidia1 device is out of service
NodeName=tux[0-2] Name=gpu File=/dev/nvidia[0-3]
NodeName=tux3 Name=gpu File=/dev/nvidia[0,2-3]
NodeName=tux[4-15] Name=gpu File=/dev/nvidia[0-3]

##################################################################
# Slurm's Generic Resource (GRES) configuration file
# Use NVML to gather GPU configuration information
# Information about all other GRES gathered from slurm.conf
##################################################################
AutoDetect=nvml

COPYING
Copyright (C) 2010 The Regents of the University of California. Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
Copyright (C) 2010-2019 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

slurm.conf(5)