January 2026 - slurm-users - lists.schedmd.com

Can I update when jobs are running?
by Gould, Ron (GRC-VBA0)[AEGIS] 21 Jan '26

21 Jan '26

The tl;dr is “This is my first upgrade since inheriting this Cluster, so I’m not sure what can or can’t be running during the upgrades.”. My Cluster is running an old version, 22.05.3. This is my first upgrade since inheriting the Cluster. As such, I’d like to install 22.05.4 because it’s a short jump, and it fixes the bug my users are seeing. The Cluster is composed of mostly Oracle Linux 8. I’m aware that I can upgrade within the two release compatibility window. I’ve read through the Upgrade guide and I’m unclear if downtime is required. Perhaps I’m unifying downtime requirements across different SLURM services where I should be interpreting that certain services have their own downtime requirements. https://slurm.schedmd.com/upgrades.html<https://slurm.schedmd.com/upgrades.html#procedure> In the Upgrade Procedure section<https://slurm.schedmd.com/upgrades.html#procedure>, there’re a couple questionable things. 1. Is downtime required? Does downtime == “all jobs must be halted”? “Downtime”, to me, seems like nothing should be running. This statement indicates that jobs can be running during the upgrade. Before considering the upgrade complete, wait for all jobs that were already running to finish. Any jobs started before the slurmd system was upgraded will be running with the old version of slurmstepd, so starting another upgrade or trying to use new features in the new version may cause problems. within a few paragraphs<https://slurm.schedmd.com/upgrades.html#downtime>, this message indicates I will need downtime: Refer to the expected downtime guidance in the following sections for each relevant Slurm daemon Further in the guide, in SLURMD (COMPUTE NODES)<https://slurm.schedmd.com/upgrades.html#slurmd>, I read Upgrades will not interrupt running jobs as long as SlurmdTimeout is not reached during the process This implies, at least, that existing running jobs can stay running. 2. There’re conflicting suggestions of using “rpm” to install the RPMs I built with “rpmbuild". Should I use “dnf localinstall ./*.rpm”? I’m inferring that dependencies will (not) be handled correctly. NOTE: If RPM/DEB packages are used, all packages present on each system must be upgraded together instead of piecewise. … Avoid using low-level package managers like rpm or dpkg as they may not properly enforce these dependencies However, in SLURMDBD (ACCOUNTING)<https://slurm.schedmd.com/upgrades.html#slurmdbd>, this statement Upgrade the slurmdbd daemon binaries, libraries, and its systemd unit file (if used). If using RPM/DEB packages, the package manager will take care of these indicates I should be using RPM packages. Lastly, to get to a current install, I need to step through multiple versions, with the condition that jobs started with a specific major version must finish within the compatibility window. GitLab has a tool where you plug in your current and intended versions and it tells you explicitly which versions are required along the upgrade path. I’d like a similarly explicit tool for SLURM, but I infer from the Compatibility Window<https://slurm.schedmd.com/upgrades.html#compatibility_window> that I can update like so: 1. Current = 22.05.3 2. 23.11 3. 25.05 4. 26.05 That feels like a big leapfrog between versions. I’d like the practice of upgrading. Is there any detriment to upgrading at a slower pace: 1. Current = 22.05.3 2. 22.05.11 3. 23.02.8 4. 23.11.11 5. 24.05.8 6. 24.11.7 7. 25.05.6 8. 25.11.2

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opposite of --array
by Herbert Fruchtl 21 Jan '26

21 Jan '26

Folks, When I use sacct, it always shows all tasks of an array job individually. This is supposed to be switched on by --array, but it seems to be the default. How do I switch it off? Thanks in advance, Herbert -- Herbert Fruchtl (he/him) Senior Scientific Computing Officer / HPC Administrator School of Chemistry, IT Services University of St Andrews -- The University of St Andrews is a charity registered in Scotland: No SC013532

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Configless Slurm Error: failed to fetch remote configs
by Xaver Stiensmeier 20 Jan '26

20 Jan '26

Hey everyone, in the past we set up clusters with configs on each node. Now we want to explore configless. Without changing anything else, we therefore followed: https://slurm.schedmd.com/configless_slurm.html and added 'enable_configless' in the config on the master: SlurmctldParameters=cloud_dns,idle_on_node_suspend,enable_configless,reconfig_on_restart and start each worker's slurmd with the conf-server parameter: # Override systemd service to set conditional path [Service] ExecStart= ExecStart=/usr/sbin/slurmd --conf-server=master However, this leads to: slurmd: error: _fetch_child: failed to fetch remote configs: Protocol authentication error slurmd: error: _establish_configuration: failed to load configs. Retrying in 10 seconds. on the workers and on the master (/var/log/slurm/slurmctld) to: [2026-01-16T10:00:06.681] error: Munge decode failed: Invalid credential [2026-01-16T10:00:06.681] auth/munge: _print_cred: ENCODED: Thu Jan 01 00:00:00 1970 [2026-01-16T10:00:06.681] auth/munge: _print_cred: DECODED: Thu Jan 01 00:00:00 1970 [2026-01-16T10:00:06.681] error: slurm_unpack_received_msg: [[worker]:24295] auth_g_verify: REQUEST_CONFIG has authentication error: Unspecified error [2026-01-16T10:00:06.681] error: slurm_unpack_received_msg: [[worker]:24295] Protocol authentication error The munge key setup is the same as before so I don't think there is anything wrong with it unless something changes with configless (slurm.conf): AuthType=auth/munge CryptoType=crypto/munge AuthAltTypes=auth/jwt AuthAltParameters=jwt_key=/etc/slurm/jwt-secret.key I found https://groups.google.com/g/slurm-users/c/Q7FVkhx-bOs but this seems unrelated as both can talk fine with each other: worker:~$ nc -zv master 6817 Connection to master (192.168.20.169) 6817 port [tcp/*] succeeded! I tried adding more "-v" to the slurmd start, but that did not give more information. I am unsure how to debug this further. Somehow I think it must be a munge issue, but I am confused as this part hasn't changed. Best regards, Xaver

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building EL10 packages
by Brian Andrus 17 Jan '26

17 Jan '26

Hopefully someone has already busted through this wall... Currently trying to build slurm for the EL10 distros. Just tried 25.11.2 (been trying .1 as well) straight from tarball to rpms. The issue trying to build so far is that there seems to be no http-parser package in the repos (trying rocky 10 and centos stream 10). Ok, so I disable slurmrestd and rpmbuild runs. It still warns about http-parser missing, but packages come out. Now, when I try to run slurmctld/slurmdbd, I get an error: //usr/sbin/slurmctld: symbol lookup error: /usr/lib64/slurm/auth_slurm.so: undefined symbol: jwt_Base64encode / This is even on the build system... I've tried enabling developer mode even, with no luck. Starting to wonder if there is a breaking change in the EL10 distro line. Anyone have insight here? Thanks in advance, Brian Andrus

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Best practice instructions and packages for Debian/Ubuntu full-upgrade?
by Steffen Grunewald 15 Jan '26

15 Jan '26

Good morning, long story: Every two years, some time after a release of Debian or Ubuntu LTS, when evaluations have ended and configurations adapted or rewritten and some reasonable maintenance date has been agreed upon by users' representatives (and directors!) and admins, we're in the situation to perform a full-upgrade (dist-upgrade) of all the machines that keep important data (while the compute nodes just get a fresh install). With the old 9-month release cycle of Slurm, in the past there was a slim chance that the upgrade from the version provided with the old release to the new release's one was small enough (since 3*9>24), but with the new 6-month cycle (4*6=24) there will always be one version too much in between. For a more or less painless transition, the manager machine running slurmdbd and slurmctld would need an intermediate version - which is not provided by Debian or Ubuntu at the time of the upgrade. Long story shorter: Provided you run Slurm on Debian/Ubuntu: Where do you get that necessary intermediate version from? I'll have to upgrade from 22.05.8-4+deb12u3 (Bookworm) to 24.11.5-4 (Trixie) (while I'm expecting the Slurm developers to urge me to proceed to 25.11.x, I couldn't find *any* deb packages for that, plus it would immediately break Ubuntu LTS integration since Noble is at 23.11.4-1.2ubuntu5). I'd need 23.11 for Debian (Bookworm *or* Trixie) for the half-step upgrade of slurmdbd's databases, and I'd like to bump Ubuntu's version to 24.11 to eventually add our GPU machines to the cluster at a later point. Long story short: Does someone keep those intermediate versions, and maybe builds ahead of the official distro ones? I can't be alone with this problem... Thanks for any pointer, Steffen -- Steffen Grunewald, Cluster Administrator Max Planck Institute for Gravitational Physics (Albert Einstein Institute) Am Mühlenberg 1 * D-14476 Potsdam-Golm * Germany ~~~ Fon: +49-331-567 7274 Mail: steffen.grunewald(at)aei.mpg.de ~~~

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We are pleased to announce the availability of Slurm versions 25.11.2 and 25.05.6.
by Marshall Garey 15 Jan '26

15 Jan '26

We are pleased to announce the availability of Slurm versions 25.11.2 and 25.05.6. Changes in 25.11.2 include fixing potential slurmctld state save file corruption while using the rpc_queue experimental feature, preventing PMIx 5.0.8 and 5.0.9 clients from hanging when connecting to the PMIx server, correctly expanding srun filename format identifiers, and various stability issues. Changes in 25.05.6 include fixing various stability issues. The full list of changes are available in the CHANGELOG files for each version: https://github.com/SchedMD/slurm/blob/slurm-25.11/CHANGELOG/slurm-25.11.md https://github.com/SchedMD/slurm/blob/slurm-25.05/CHANGELOG/slurm-25.05.md Slurm can be downloaded from: https://www.schedmd.com/download-slurm/ -- Marshall Garey Senior System Software Engineer NVIDIA

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Build 22.05.8 for Debian Trixie?
by Steffen Grunewald 15 Jan '26

15 Jan '26

Good afternoon, we're still running our HPC cluster on Debian 12 Bookworm, which comes with Slurm 22.05.8 - no issues so far. Yesterday, another machine was added as a submit node (slurm-client only), with Debian 13 Trixie / Slurm 24.11.5. Now on that the commands (sinfo etc.) don't work and the slurmctld logs "Incompatible versions of client and server code". Since upgrading the whole cluster is not an option yet: Has someone attempted (and possibly succeeded) to build 22.05.8 (or 23.11.4? which IIRC would be the last compatible one) for Trixie, and would be willing to share ideas? Thanks, Steffen -- Steffen Grunewald, Cluster Administrator Max Planck Institute for Gravitational Physics (Albert Einstein Institute) Am Mühlenberg 1 * D-14476 Potsdam-Golm * Germany ~~~ Fon: +49-331-567 7274 Mail: steffen.grunewald(at)aei.mpg.de ~~~

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Socket memory binding (NUMA). cpu-bind possible with srun, not sbatch
by Rémy Dernat 14 Jan '26

14 Jan '26

Hi, I am looking at that useful documentation https://slurm.schedmd.com/cpu_management.html We have people complaining about memory performance issues while running highly distributed jobs in a shared HPC cluster environment. After looking into it, we saw that is either because of concurrent access to the memory with other users, or because we have jump over memory from a socket to another (in a Numa architecture). Until now, our "easy" answer was to use "exclusive" mode in sbatch, to ensure avoiding any concurrent memory access, and using numactl to check if the job is bound to the other socket. However, I am looking to a better solution, as exclusive mode took all of a big node (we have only big nodes...), and numactl just check if we will have poor performances or not. I checked the slurm.conf parameters, but all I saw is about modifying selectType. However, I cannot use other selectType as we have GPU, so we are using cons_tres. Moreover, we already have a very complicated Slurm configuration, and I would like to avoid any side effect. I am thinking about talking to our user about the `--cpu-bind` (https://slurm.schedmd.com/srun.html#OPT_cpu-bind) method, but I am not sure how to use it, and it seems to be limited to srun ... ? From a job point of view, I know there are some programs to deal with that, like likwid or placement (but not entirely ?), but that does not seem easy to use, and a slurm would be more suitable and more generic. Do you have any idea on how to deal with these issues ? Thanks, Best regards, Rémy Dernat

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slurmctld hourly: Unexpected missing socket error
by Jason Ellul 13 Jan '26

13 Jan '26

Hi all, I am hoping someone can help with our problem. Every hour after restarting slurmctld the controller becomes unresponsive to commands for 1 sec, reporting errors such as: [2024-07-15T11:45:48.509] error: slurm_send_node_msg: [socket:[934767]] slurm_bufs_sendto(msg_type=RESPONSE_JOB_INFO) failed: Unexpected missing socket error [2024-07-15T11:45:48.509] error: slurm_send_node_msg: [socket:[934760]] slurm_bufs_sendto(msg_type=RESPONSE_SLURM_RC) failed: Unexpected missing socket error [2024-07-15T11:45:48.509] error: slurm_send_node_msg: [socket:[934875]] slurm_bufs_sendto(msg_type=RESPONSE_JOB_INFO) failed: Unexpected missing socket error [2024-07-15T11:45:48.509] error: slurm_send_node_msg: [socket:[934906]] slurm_bufs_sendto(msg_type=RESPONSE_JOB_INFO) failed: Unexpected missing socket error [2024-07-15T11:45:48.509] error: slurm_send_node_msg: [socket:[939016]] slurm_bufs_sendto(msg_type=RESPONSE_JOB_INFO) failed: Unexpected missing socket error It occurs consistently at around the hour mark, but generally not at other times, unless we run a reconfigure or restart the controller. We don’t see any issues in the slurmdbd.log and the errors are also always msg type RESPONSE. We have tried building a new server on different infrastructure, but the problem has persisted. Yesterday we even tried updating slurm to v24.05.1 in the hope that may provide a fix. During our troubleshooting we have: Set: * SchedulerParameters = max_rpc_cnt=400,sched_min_interval=50000,sched_max_job_start=300,batch_sched_delay=20,bf_resolution=600,bf_min_prio_reserve=2000,bf_min_age_reserve=600 * SlurmctldPort = 6808-6817 But although the stats in sdiag have improved we still see the errors. On our monitoring software we also see a drop in network and disk activity during this 1 second, always at approx. 1 hour after restarting the controller. Many Thanks in advance Jason Jason Ellul Head - Research Computing Facility Office of Cancer Research Peter MacCallum Cancer Centre

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'sacct -a' missing running jobs 'held' by user
by Lee 08 Jan '26

08 Jan '26

Hello, I am using slurm 23.02.6. I have a strange issue. I periodically use sacct to dump job data. I then generate reports based on the resource allocation of our users. Recently, I noticed some 'missing' jobs from my query. The missing jobs came from a user who had a large array job, who then 'held' all of the array jobs. This included 'holding' the Running array jobs. Now, if I run `sacct -a -S YYYY-MM-DD --format="jobidraw,jobname"`, the job will be missing from that query. However, if I query specifically for that job, i.e. `sacct -j RAWJOBID -S YYYY-MM-DD --format="jobidraw,jobname", the job is present. *Question* : 1. How can I include the 'held' running job when I do my bulk query with `sacct -a`? Finding these outliers and adding them ad-hoc to my dumped file is too laborious and isn't feasible. *Minimum working example *: #. Submit a job : myuser@clusterb01:~$ srun --pty bash # landed on dgx29 #. Hold job myuser@clusterb01:~$ scontrol hold 120918 myuser@clusterb01:~$ scontrol show job=120918 JobId=120918 JobName=bash UserId=myuser(123456) GroupId=rdusers(7000) MCS_label=N/A Priority=0 Nice=0 Account=allusers QOS=normal JobState=*RUNNING* Reason=*JobHeldUser* Dependency=(null) Requeue=0 Restarts=0 BatchFlag=0 Reboot=0 ExitCode=0:0 RunTime=00:00:29 TimeLimit=7-00:00:00 TimeMin=N/A SubmitTime=2025-12-15T13:31:28 EligibleTime=Unknown AccrueTime=Unknown StartTime=2025-12-15T13:31:28 EndTime=2025-12-22T13:31:28 Deadline=N/A SuspendTime=None SecsPreSuspend=0 LastSchedEval=2025-12-15T13:31:28 Scheduler=Main Partition=defq AllocNode:Sid=clusterb01:4145861 ReqNodeList=(null) ExcNodeList=(null) NodeList=dgx29 BatchHost=dgx29 NumNodes=1 NumCPUs=2 NumTasks=1 CPUs/Task=1 ReqB:S:C:T=0:0:*:* ReqTRES=cpu=1,mem=9070M,node=1,billing=1 AllocTRES=cpu=2,mem=18140M,node=1,billing=2 Socks/Node=* NtasksPerN:B:S:C=0:0:*:* CoreSpec=* MinCPUsNode=1 MinMemoryCPU=9070M MinTmpDiskNode=0 Features=(null) DelayBoot=00:00:00 OverSubscribe=OK Contiguous=0 Licenses=(null) Network=(null) Command=bash WorkDir=/home/myuser Power= #. Release job myuser@clusterb01:~$ scontrol release 120918 #. Show job again myuser@clusterb01:~$ scontrol show job=120918 JobId=120918 JobName=bash UserId=myuser(123456) GroupId=rdusers(7000) MCS_label=N/A Priority=1741 Nice=0 Account=allusers QOS=normal JobState=*RUNNING* Reason=*None* Dependency=(null) Requeue=0 Restarts=0 BatchFlag=0 Reboot=0 ExitCode=0:0 RunTime=00:01:39 TimeLimit=7-00:00:00 TimeMin=N/A SubmitTime=2025-12-15T13:31:28 EligibleTime=Unknown AccrueTime=Unknown StartTime=2025-12-15T13:31:28 EndTime=2025-12-22T13:31:28 Deadline=N/A SuspendTime=None SecsPreSuspend=0 LastSchedEval=2025-12-15T13:31:28 Scheduler=Main Partition=defq AllocNode:Sid=clusterb01:4145861 ReqNodeList=(null) ExcNodeList=(null) NodeList=dgx29 BatchHost=dgx29 NumNodes=1 NumCPUs=2 NumTasks=1 CPUs/Task=1 ReqB:S:C:T=0:0:*:* ReqTRES=cpu=1,mem=9070M,node=1,billing=1 AllocTRES=cpu=2,mem=18140M,node=1,billing=2 Socks/Node=* NtasksPerN:B:S:C=0:0:*:* CoreSpec=* MinCPUsNode=1 MinMemoryCPU=9070M MinTmpDiskNode=0 Features=(null) DelayBoot=00:00:00 OverSubscribe=OK Contiguous=0 Licenses=(null) Network=(null) Command=bash WorkDir=/home/myuser/ Power= #. In slurmctld, I see : root@clusterb01:~# grep 120918 /var/log/slurmctld [2025-12-15T13:31:28.706] sched: _slurm_rpc_allocate_resources JobId=120918 NodeList=dgx29 usec=1269 [2025-12-15T13:31:47.751] sched: _hold_job_rec: hold on JobId=120918 by uid 123456 [2025-12-15T13:31:47.751] sched: _update_job: set priority to 0 for JobId=120918 [2025-12-15T13:31:47.751] _slurm_rpc_update_job: complete JobId=120918 uid=123456 usec=189 [2025-12-15T13:32:48.081] sched: _release_job_rec: release hold on JobId=120918 by uid 123456 [2025-12-15T13:32:48.081] _slurm_rpc_update_job: complete JobId=120918 uid=123456 usec=268 [2025-12-15T13:33:20.552] _job_complete: JobId=120918 WEXITSTATUS 0 [2025-12-15T13:33:20.552] _job_complete: JobId=120918 done #. Job is NOT missing, when identifying it by jobid myuser@clusterb01:~$ sacct -j 120918 --starttime=2025-12-12 -o "jobidraw,jobid,node,start,end,elapsed,state,submitline%30" JobIDRaw JobID NodeList Start End Elapsed State SubmitLine ------------ ------------ --------------- ------------------- ------------------- ---------- ---------- ------------------------------ 120918 120918 dgx29 2025-12-15T13:31:28 2025-12-15T13:33:20 00:01:52 COMPLETED srun --pty bash 120918.0 120918.0 dgx29 2025-12-15T13:31:28 2025-12-15T13:33:20 00:01:52 COMPLETED srun --pty bash #. Job IS *missing* when using -a myuser@clusterb01:~$ sacct -a --starttime=2025-12-12 -o "jobidraw,jobid,node,start,end,elapsed,state,submitline%30" | grep -i 120918 ## *MISSING* Best regards, Lee

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