burst_buffer.conf(5)

💖 burst_buffer.conf — the Slurm config file for burst buffer management 💖

okay bestie, welcome to burst_buffer.conf, the manual page number 5 in the Slurm Configuration File collection. this is where you tell Slurm how to run its burst buffers, and yes it's giving main character energy for your whole cluster's scratch space. let's get into it 🫶

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✨ NAME ✨

burst_buffer.conf — Slurm configuration file for burst buffer management. that's it. that's the name. iconic.

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🌸 DESCRIPTION 🌸

burst_buffer.conf is an ASCII file that describes the configuration of burst buffer resource management. no cap, plain text, we love a file you can read with your eyeballs.

This file is only required on the head node(s), aka where the slurmctld daemon does its thing. the file will always live in the same directory as your slurm.conf. they're roommates. they're a package deal. 💅

Some housekeeping rules, so listen up:

• Parameter names are case insensitive. type it however you want, Slurm is not gonna fight you on vibes.
• Any text following a # in the configuration file is treated as a comment through the end of that line. so # is the mute button, basically.
• 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.

lowkey important: editing the file alone does nothing until one of those three things happens. don't just save and ✨manifest✨ it, fr fr.

The configuration parameters available include:

• AllowUsers — comma separated list of user names and/or IDs permitted to use burst buffers. The options AllowUsers and DenyUsers can not both be specified. By default all users are permitted to use burst buffers. so it's a guest list situation, and you can't have both a guest list AND a banned list, pick a lane bestie 😭
• DefaultPool — name of the pool used by default for resource allocations. The default value is the first pool reported by the burst buffer infrastructure. This option is only used by the burst_buffer/datawarp plugin.
• DenyUsers — colon delimited list of user names and/or IDs prevented from using burst buffers. (yes, colon delimited, not comma like AllowUsers — the inconsistency is a whole thing, we don't talk about it 💀) The options AllowUsers and DenyUsers can not both be specified. By default all users are permitted to use burst buffers.
• Directive — the string that must be used by a job to request a burst buffer. This string must be immediately preceded by a single # character. This is currently only used by the lua plugin. For the lua plugin, the default value is "BB_LUA". See burst_buffer.html for more details. so the job writes like #BB_LUA and Slurm goes "say less, buffer incoming" 🦋
• Flags — string used to control various functions. Multiple options may be comma separated. Supported options include:
  • DisablePersistent — prevents regular users from being able to create and destroy persistent burst buffers. This is the default behavior, only privileged users (Slurm operators and administrators) can create or destroy persistent burst buffers.
  • EmulateCray — emulating a Cray DataWarp system using the dw_wlm_cli script in the burst_buffer/datawarp plugin. This is only used by the datawarp plugin.
  • EnablePersistent — enables regular users to create and destroy persistent burst buffers. By default, only privileged users (Slurm operators and administrators) can create or destroy persistent burst buffers. This is only used by the datawarp plugin.
  • PrivateData — if set, then only Slurm operators and the burst buffer owner can see burst buffer data.
  • TeardownFailure — if set, then teardown a burst buffer after file staging error. Otherwise preserve the burst buffer for analysis and manual teardown. (so if you don't set this, the busted buffer sticks around so you can go snoop on it yourself 🔍)
• GetSysState — fully qualified path name of a program which will return the current burst buffer state. For the DataWarp plugin, this should be the path of the dw_wlm_cli command and its default value is /opt/cray/dw_wlm/default/bin/dw_wlm_cli. This is not used by the lua plugin.
• GetSysStatus — fully qualified path name of a program which will return the current burst buffer status. For the DataWarp plugin, this should be the path of the dwstat command and its default value is /opt/cray/dws/default/bin/dwstat. This is not used by the lua plugin.
• OtherTimeout — if a burst buffer operation (other than job validation, stage in, or stage out) runs for longer than this number of seconds, the job will be placed in a held state. A Slurm administrator will be required to release the job. By default there is a 300 second (5 minute) timeout for these operations. Also see StageInTimeout, StageOutTimeout, and ValidateTimeout options. For the lua plugin, the maximum timeout value is 2073600 seconds (24 days).
• PollInterval — this option only applies to the lua plugin. If the test_data_{in|out} hooks return success and "BUSY", then they will be called again after waiting for the specified number of seconds. The default value is 15 seconds. so it's the "are we there yet" check-in cadence 💀
• PrivateData — if set to "true" then users will only be able to view burst buffers they can use. Slurm administrators will still be able to view all burst buffers. By default, users can view all burst buffers.
• StageInTimeout — if the stage in of files for a job takes more than this number of seconds, the burst buffer will be released and the job will be placed in a held state. A Slurm administrator will be required to release the job. By default there is a one day timeout for the stage in process. For the lua plugin, the maximum timeout value is 2073600 seconds (24 days).
• StageOutTimeout — if the stage out of files for a job takes more than this number of seconds, the burst buffer will be released and the job will be purged. By default there is a one day timeout for the stage out process. For the lua plugin, the maximum timeout value is 2073600 seconds (24 days).
• ValidateTimeout — if the validation of a job submission request takes more than this number of seconds, the submission will be rejected. The value of ValidateTimeout must be less than the value of MessageTimeout configured in the slurm.conf file or job submission requests may fail with a response timeout error. By default there is a 5 second timeout for the validation operations. In the lua plugin, because the validation operation cannot be killed, this option is not used.

bestie, note that PrivateData shows up twice in this config — once as a Flags value and once as its own standalone parameter. they're not the same thing, don't merge them in your head, i'm begging 🙈

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👑 COPYING 👑

Copyright (C) 2014-2022 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.

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🎀 SEE ALSO 🎀

• slurm.conf(5)

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and that's the whole page, babes 💜 this was Slurm 26.05, filed under Slurm Configuration File, page 5 — the burst_buffer.conf(5) manual. go configure your buffers, you've got this. periodt ✨🫶🌸