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MIG and eBPF issues (Slurm 24.11.6)
by wk5ng＠uwaterloo.ca 28 Nov '25

28 Nov '25

Hi all, I'm having some trouble getting Slurm 24.11.6 to work with MIG, and the slurmd logs seem to point to an issue with eBPF. For some context, this is an LXD unprivileged container where I'm trying to get MIG to work with Slurm. Other compute nodes without MIG work fine and isolate the GPUs accordingly. What I'm seeing in slurmd logs: [2025-11-24T23:32:50.197] [331.interactive] cgroup/v2: cgroup_p_constrain_apply: CGROUP: EBPF Closing and loading bpf program into /sys/fs/cgroup/system.slice/slurmstepd.scope/job_331 [2025-11-24T23:32:50.197] [331.interactive] error: load_ebpf_prog: BPF load error (Operation not permitted). Please check your system limits (MEMLOCK). I've tried increasing the system limits for MEMLOCK by setting DefaultLimitMEMLOCK=infinity in /etc/systemd/system.conf, and I've copied my slurmd.service file below where I've set Delegate=yes and LimitMEMLOCK=infinity. Previously only Delegate=yes wasn't set (I had rifled through the cgroupv2 documentaton for Slurm and found that setting), but in both cases I see the same BPF load error. Just wondering if this was something that other people had come across before and maybe I'm doing something silly here. I've checked that my slurm.conf has the corresponding parameters set according to Slurm's own documentation for cgroup.conf and my cgroup.conf is also copied below. Some portion of the gres.conf is also copied below, and even though I tried AutoDetect=nvml for this node, it's still doesn't work, which was why I changed to manually setting it based off the output of slurmd -G. Maybe I should try switching back to cgroupv1 and see if that helps fix things, but I'm not sure at this point if MIG and Slurm are compatible using cgroupv1. I can send other parts of logs, configuration files etc. Any help would be greatly appreciated! ###### slurmd.service file [Unit] Description=Slurm node daemon After=network.target munge.service ConditionPathExists=/etc/slurm/slurm.conf [Service] Type=forking EnvironmentFile=-/etc/sysconfig/slurmd ExecStart=/usr/sbin/slurmd -d /usr/sbin/slurmstepd $SLURMD_OPTIONS ExecReload=/bin/kill -HUP $MAINPID PIDFile=/var/run/slurmd.pid KillMode=process LimitNOFILE=51200 Delegate=yes LimitMEMLOCK=infinity LimitSTACK=infinity [Install] WantedBy=multi-user.target ###### cgroup.conf CgroupPlugin=autodetect ConstrainCores=yes ConstrainDevices=yes ConstrainRAMSpace=yes ##### gres.conf NodeName=gpu-3 AutoDetect=nvml Name=gpu NodeName=gpu-4 Name=gpu MultipleFiles=/dev/nvidia0,/dev/nvidia-caps/nvidia-cap30,/dev/nvidia-caps/nvidia-cap31

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Slinky version 1.0.0 is now available
by Marrlow Warnicke 20 Nov '25

20 Nov '25

We are pleased to announce the availability of Slinky version 1.0.0! Slinky is SchedMD's set of components to integrate Slurm in Kubernetes environments. Slinky consists of two main projects, slurm-operator and slurm-bridge. Our landing page is here: https://www.slinky.ai The slurm-operator handles cases where users wish to run Slurm jobs within the Kubernetes cluster. Release v1.0.0: https://github.com/SlinkyProject/slurm-operator/tree/release-1.0 New features include hybrid support, integration points for external tooling, and workload protection and isolation. The full changelog may be found here: https://github.com/SlinkyProject/slurm-operator/blob/main/CHANGELOG/CHANGEL… The slurm-bridge handles the cases where you want Slurm scheduling on your cluster and to be able to run either Kubernetes or Slurm jobs. Release v1.0.0: https://github.com/SlinkyProject/slurm-bridge/tree/release-1.0 New features include support for DRA Extended Resources, support for TaintToleration and VolumeBinding plugins, and integration of new Slurm 25.11 support for granular node resource allocation assignments with GRES. The full changelog may be found here: https://github.com/SlinkyProject/slurm-bridge/blob/main/CHANGELOG/CHANGELOG… The SlinkyProject registry now has containers that support both amd64 (x86_64) and arm64 (aarch64) architectures. You may find these here: https://github.com/orgs/SlinkyProject/packages Apologies for the redundant email-we needed to clarify the release version. -- Marlow Warnicke Principal Cloud Engineer Commercial Slurm - and Slinky - Development and Support

1 0

Slinky version 1.0.0 is now available
by Marrlow Warnicke 20 Nov '25

20 Nov '25

We are pleased to announce the availability of Slinky version 1.0.0-rc1. Slinky is SchedMD’s set of components to integrate Slurm in Kubernetes environments. Slinky consists of two main projects, slurm-operator and slurm-bridge. Our landing page is here: https://www.slinky.ai The slurm-operator handles cases where users wish to run Slurm jobs within the Kubernetes cluster. Release v1.0.0-rc1: https://github.com/SlinkyProject/slurm-operator/tree/release-1.0 New features include hybrid support, integration points for external tooling, and workload protection and isolation. The full changelog may be found here: https://github.com/SlinkyProject/slurm-operator/blob/main/CHANGELOG/CHANGEL… The slurm-bridge handles the cases where you want Slurm scheduling on your cluster and to be able to run either Kubernetes or Slurm jobs. Release v1.0.0-rc1: https://github.com/SlinkyProject/slurm-bridge/tree/release-1.0 New features include support for DRA Extended Resources, support for TaintToleration and VolumeBinding plugins, and integration of new Slurm 25.11 support for granular node resource allocation assignments with GRES. The full changelog may be found here: https://github.com/SlinkyProject/slurm-bridge/blob/main/CHANGELOG/CHANGELOG… The SlinkyProject registry now has containers that support both amd64 (x86_64) and arm64 (aarch64) architectures. You may find these here: https://github.com/orgs/SlinkyProject/packages -- Marlow Warnicke Principal Cloud Engineer, SchedMD LLC Commercial Slurm - and Slinky - Development and Support

1 0

Recommended Stable Slurm Version for >100P Scale Clusters
by KK 18 Nov '25

18 Nov '25

We are currently planning to deploy a new HPC system with a total compute capacity exceeding 100 PF. As part of our preparation, we would like to understand which Slurm versions are considered stable and widely used at this scale. Could you please share your recommendations or experience regarding: 1. Which Slurm version is currently running reliably on very large-scale clusters (>100 PF or >10k nodes)? 2. Whether there are any versions we should avoid due to known issues at large scale. 3. Any best practices or configuration considerations for Slurm deployments of this size.

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Slurm versions 25.05.5 and 24.11.7 are now available
by Marshall Garey 11 Nov '25

11 Nov '25

We are pleased to announce the availability of Slurm versions 25.05.5 and 24.11.7. These releases fix some mild to moderate severity issues and potential crashes. The full list of changes are available in the CHANGELOG files for each version: https://github.com/SchedMD/slurm/blob/slurm-25.05/CHANGELOG/slurm-25.05.md https://github.com/SchedMD/slurm/blob/slurm-24.11/CHANGELOG/slurm-24.11.md Slurm can be downloaded from: https://www.schedmd.com/download-slurm/ -- Marshall Garey Release Management, Support, and Development SchedMD LLC - Commercial Slurm Development and Support

1 0

Split node into 2 partitions
by Ratnasamy, Fritz 11 Nov '25

11 Nov '25

Hi, Is there a straightforward way to split a gpu node with 8 GPUs into 2 partitions with 4 GPUs on each? How do we edit the slurm.conf and gres.conf in this case? Thanks, *Fritz Ratnasamy*Data Scientist Information Technology

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Slurm Community Survey 2025
by Tim Wickberg 10 Nov '25

10 Nov '25

With the Slurm 25.11 release out, and the 1.0.0rc1 for the Slinky Project done, we're quickly shifting into conference season. SchedMD staff are presenting at KubeCon North America on Slinky [1] this week. We don't have a booth here, but feel free to say hi if you see any of us, or send me a message on the Kubernetes or CNCF Slack channels (@wickberg) if you have something you'd like to discuss in person. Next week we'll be manning the Slurm Booth at SC25 [2], as well as hosting the annual Slurm Community Birds-of-a-Feather session [3] on Thursday from 12:15-1:15pm. For this year we wanted to to make the Slurm Community BoF survey available ahead of time, and to open it to a wider audience. This'll let us prepare some initial results ahead of the BoF (while still trying to update live data during the BoF), and the results from this are invaluable as we plan for future Slurm releases. The survey is available now: https://schedmd.com/survey For those not at SC25, we'll have a brief set of highlights from this survey included in the Slurm 25.11 release overview video on our YouTube channel in December. - Tim [1] https://kccncna2025.sched.com/event/27FW5/ [2] The Slurm Booth is #1641. We have a new halo banner this year as well. [3] https://sc25.conference-program.com/presentation/?id=bof101&sess=sess471 [4] https://www.youtube.com/SchedMDSlurm -- Tim Wickberg Chief Technology Officer, SchedMD LLC Commercial Slurm Development and Support

1 0

sreport and AccountUtilizationByUser
by Gestió Servidors 08 Nov '25

08 Nov '25

Hello, I woud like to get a full report that includes CPU usage of an account (detalied by user). I have run "sreport cluster AccountUtilizationByUser start=9/1 end=11/2 account=mygr" and the output is this: -------------------------------------------------------------------------------- Cluster/Account/User Utilization 2025-09-01T00:00:00 - 2025-11-01T23:59:59 (5360400 secs) Usage reported in CPU Minutes -------------------------------------------------------------------------------- Cluster Account Login Proper Name Used Energy --------- --------------- --------- --------------- --------- -------- mycluster mygr 3979368 0 mycluster mygr mygr-1 3979368 0 mycluster mygr mygr-10 3979368 0 mycluster mygr mygr-11 3979368 0 mycluster mygr mygr-12 3979368 0 mycluster mygr mygr-13 3979368 0 mycluster mygr mygr-14 3979368 0 mycluster mygr mygr-15 3979368 0 mycluster mygr mygr-16 3979368 0 mycluster mygr mygr-17 3979368 0 mycluster mygr mygr-18 3979368 0 mycluster mygr mygr-19 3979368 0 mycluster mygr mygr-2 3979368 0 mycluster mygr mygr-20 3979368 0 mycluster mygr mygr-21 3979368 0 mycluster mygr mygr-22 3979368 0 mycluster mygr mygr-23 3979368 0 mycluster mygr mygr-24 3979368 0 mycluster mygr mygr-25 3979368 0 mycluster mygr mygr-26 3979368 0 mycluster mygr mygr-27 3979368 0 mycluster mygr mygr-28 3979368 0 mycluster mygr mygr-29 3979368 0 mycluster mygr mygr-3 3979368 0 mycluster mygr mygr-30 3979368 0 mycluster mygr mygr-31 3979368 0 mycluster mygr mygr-32 3979368 0 mycluster mygr mygr-33 3979368 0 mycluster mygr mygr-34 3979368 0 mycluster mygr mygr-35 3979368 0 mycluster mygr mygr-36 3979368 0 mycluster mygr mygr-37 3979368 0 mycluster mygr mygr-38 3979368 0 mycluster mygr mygr-39 3979368 0 mycluster mygr mygr-4 3979368 0 mycluster mygr mygr-40 3979368 0 mycluster mygr mygr-5 3979368 0 mycluster mygr mygr-6 3979368 0 mycluster mygr mygr-7 3979368 0 mycluster mygr mygr-8 3979368 0 mycluster mygr mygr-9 3979368 0 I don't understand why column "Used" shows always the same value, because each user "mygr-XX" has used the cluster in differents ways, times and each used has submitted very different number of jobs, as you can see in this "sshare" output: [root@login bin]# sshare -l -A mygr Account User RawShares NormShares RawUsage NormUsage EffectvUsage FairShare LevelFS -------------------- ---------- ---------- ----------- ----------- ----------- ------------- ---------- ---------- mygr 1 0.250000 3941705 0.337402 0.961033 0.260137 mygr mygr-1 1 0.024390 32099 0.002748 0.008144 0.095146 2.995008 mygr mygr-10 1 0.024390 98343 0.008418 0.024949 0.067961 0.977586 mygr mygr-11 1 0.024390 213838 0.018304 0.054250 0.052427 0.449588 mygr mygr-12 1 0.024390 134149 0.011483 0.034033 0.056311 0.716657 mygr mygr-13 1 0.024390 89304 0.007644 0.022656 0.071845 1.076537 mygr mygr-14 1 0.024390 524836 0.044925 0.133150 0.040777 0.183179 mygr mygr-15 1 0.024390 303494 0.025979 0.076996 0.044660 0.316774 mygr mygr-16 1 0.024390 99020 0.008476 0.025121 0.066019 0.970897 mygr mygr-17 1 0.024390 296341 0.025366 0.075181 0.046602 0.324421 mygr mygr-18 1 0.024390 37809 0.003236 0.009592 0.085437 2.542696 mygr mygr-19 1 0.024390 72158 0.006177 0.018306 0.077670 1.332337 mygr mygr-2 1 0.024390 225658 0.019316 0.057249 0.050485 0.426039 mygr mygr-20 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-21 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-22 1 0.024390 115042 0.009847 0.029186 0.062136 0.835683 mygr mygr-23 1 0.024390 54169 0.004637 0.013743 0.081553 1.774775 mygr mygr-24 1 0.024390 125767 0.010765 0.031907 0.058252 0.764422 mygr mygr-25 1 0.024390 243088 0.020808 0.061671 0.048544 0.395490 mygr mygr-26 1 0.024390 35516 0.003040 0.009010 0.089320 2.706902 mygr mygr-27 1 0.024390 65281 0.005588 0.016562 0.079612 1.472682 mygr mygr-28 1 0.024390 118203 0.010118 0.029988 0.060194 0.813335 mygr mygr-29 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-3 1 0.024390 107543 0.009206 0.027284 0.064078 0.893956 mygr mygr-30 1 0.024390 33946 0.002906 0.008612 0.091262 2.832099 mygr mygr-31 1 0.024390 183059 0.015670 0.046442 0.054369 0.525180 mygr mygr-32 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-33 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-34 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-35 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-36 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-37 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-38 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-39 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-4 1 0.024390 37605 0.003219 0.009541 0.087379 2.556486 mygr mygr-40 1 0.024390 0 0.000000 0.000000 0.118447 inf mygr mygr-5 1 0.024390 81114 0.006943 0.020578 0.073786 1.185232 mygr mygr-6 1 0.024390 91873 0.007864 0.023308 0.069903 1.046428 mygr mygr-7 1 0.024390 80513 0.006892 0.020426 0.075728 1.194082 mygr mygr-8 1 0.024390 367822 0.031485 0.093316 0.042718 0.261374 mygr mygr-9 1 0.024390 33630 0.002879 0.008532 0.093204 2.858713 mygr mygr-tutor 1 0.024390 40472 0.003464 0.010268 0.083495 2.375427 What am I doing wrong? What I need to get is a detalied report from all "mygr" users (mygr account) from CPU usage and, if it is possible, other values. Thanks.

2 1

Slinky version 1.0.0rc1 is now now available
by Marrlow Warnicke 07 Nov '25

07 Nov '25

We are pleased to announce the availability of Slinky version 1.0.0-rc1. Slinky is SchedMD’s set of components to integrate Slurm in Kubernetes environments. Slinky consists of two main projects, slurm-operator and slurm-bridge. Our landing page is here: https://www.slinky.ai The slurm-operator handles cases where users wish to run Slurm jobs within the Kubernetes cluster. Release v1.0.0-rc1: https://github.com/SlinkyProject/slurm-operator/tree/release-1.0 New features include hybrid support, integration points for external tooling, and workload protection and isolation. The full changelog may be found here: https://github.com/SlinkyProject/slurm-operator/blob/main/CHANGELOG/CHANGEL… The slurm-bridge handles the cases where you want Slurm scheduling on your cluster and to be able to run either Kubernetes or Slurm jobs. Release v1.0.0-rc1: https://github.com/SlinkyProject/slurm-bridge/tree/release-1.0 New features include support for DRA Extended Resources, support for TaintToleration and VolumeBinding plugins, and integration of new Slurm 25.11 support for granular node resource allocation assignments with GRES. The full changelog may be found here: https://github.com/SlinkyProject/slurm-bridge/blob/main/CHANGELOG/CHANGELOG… The SlinkyProject registry now has containers that support both amd64 (x86_64) and arm64 (aarch64) architectures. You may find these here: https://github.com/orgs/SlinkyProject/packages -- Marlow Warnicke Principal Cloud Engineer, SchedMD LLC Commercial Slurm - and Slinky - Development and Support

1 0

submit host DNS lookup errors stall slurmctld, fail nodes, kill jobs
by moorehfl＠amazon.com 06 Nov '25

06 Nov '25

As we've scaled up our slurm usage, we've noticed that short, moderate bursts of DNS lookup failures are enough to regularly stall slurmctld: _xgetaddrinfo: getaddrinfo(runner-t35knco5d-project-54-concurrent-0:37251) failed ...this has a cascading effect where, when stalled, the controlled can't always communicate with nodes: error: Error connecting, bad data: family = 0, port = 0 ...and immediately the controller will mark the nodes as unhealthy, and kill jobs: slurmctld: Killing JobId=3120751 on failed node slurm-0f6cacdc1 The reason for the DNS failures is not unreliable DNS server or network, but rather the jobs are submitted by containers that don't have resolvable hostnames. This traditionally hasn't disrupted functionality, but we've noticed if 8-10 jobs all terminate at the same time (submitter container SIGTERMs the srun process) that the controller can be easily overloaded for several seconds, despite having significant free system resources. gdb confirms the process is hanging on DNS. We also can see "Socket timed out on send/recv operation" from clients attempting to interact with the controller during the issue. slurm 24.11.0 RHEL 8.10 kernel 4.18.0-553.58.1.el8_10.x86_64 We're looking into ways to get our ephemeral job submitter containers resolvable in DNS to prevent lookup failures (either by giving them resolvable hostnames, or by blackholing the records to 0.0.0.0 to allow for fast local failure on the slurmctld server). However, it does seem unusual for a handful of bad DNS lookups to cause so much disruption in slurmctld. Is this a known weak point of ctld? The slurmctld host is a single-purpose 16 vCPU 30GB EC2 instance with minimal load. We have ~150 nodes, all nodes have valid IPs in slurm.conf to remove the need for ctld to perform lookups for nodes, but apparently there is still a need to lookup the submit host as well, and we can reliably reproduce these cascading failures. Another possiblity might be to extend SlurmdTimeout to something very long and hope that the controller recovers from its stall in enough time to prevent from marking nodes as unhealthy and killing jobs, but it's not clear if that will have any effect since the first occurrence of "error: Error connecting, bad data: family = 0, port = 0" immediately drains nodes and kills jobs. Thanks

1 0

Slurm version 25.11 is now available
by Marshall Garey 06 Nov '25

06 Nov '25

We are pleased to announce the availability of Slurm 25.11. The release notes summarizing the new features, and including links to the corresponding documentation, can be found at: https://slurm.schedmd.com/release_notes.html A more extensive list of changes are available in the CHANGELOG: https://github.com/SchedMD/slurm/blob/slurm-25.11/CHANGELOG/slurm-25.11.md The Slurm documentation has also been updated to the 25.11 release: https://slurm.schedmd.com Slurm can be downloaded from: https://www.schedmd.com/download-slurm/ -- Marshall Garey Release Management, Support, and Development SchedMD LLC - Commercial Slurm Development and Support

1 0

CPU frequency setting not configured for this node
by Felix 06 Nov '25

06 Nov '25

Hello I get this error: "CPU frequency setting not configured for this node" in some of my node. I do not know what to do, can you please advice. Thank you Felix -- Dr. Eng. Farcas Felix National Institute of Research and Development of Isotopic and Molecular Technology, IT - Department - Cluj-Napoca, Romania Mobile: +40742195323

1 0

Move to higher qos when cluster idle
by Ratnasamy, Fritz 06 Nov '25

06 Nov '25

Hi, Is there an option to automatically have users move to a higher qos when the cluster is x% idle? I was reading about customizing the job_submit.lua script in order to do that but I was wondering if it makes sense. We have a gpu cluster and many users complain they can not allocate more than their current qos when the cluster is not very busy. Best, *Fritz Ratnasamy*Data Scientist Information Technology

1 0

Slurm release candidate version 25.11.0rc1 is available for testing
by Tim Wickberg 28 Oct '25

28 Oct '25

We are pleased to announce the availability of Slurm release candidate 25.11.0rc1. To highlight some new features coming in 25.11: * Added new "Expedited Requeue" mode for batch jobs. Batch jobs with --requeue=expedite will automatically requeue on node failure, or if the batch script returns a non-zero exit code and one or more Epilog scripts fail. Expedited requeue jobs are eligible to restart immediately, are treated as the highest priority job in the system, and their previously allocated set of nodes will be prevented from launching other work. * Added a new "Mode 3" of operation to Hierarchical Resources. This mode complements the existing Mode 1 and Mode 2 by summing usage from lower levels automatically. This can be used, e.g., to implement a power-capping mode modeling power distribution between the datacenter, local distribution, and individual racks. * Added direct support for exporting OpenMetrics (Prometheus) telemetry from slurmctld. This is accessible on SlurmctldPort on SlurmctldHost by default, or can be disabled if desired. * Added an experimental asynchronous-reply mode to slurmctld. If enabled with "SlurmctldParameters=enable_async_reply", RPC responses are offloaded to the kernel for further processing, freeing individual worker threads for new traffic. This is the first release candidate of the upcoming 25.11 release series, and represents the end of development for this release, and a finalization of the RPC and state file formats. If any issues are identified with this release candidate, please report them through https://bugs.schedmd.com against the 25.11.x version and we will address them before the first production 25.11.0 release is made. Please note that the release candidates are not intended for production use. A preview of the updated documentation can be found at https://slurm.schedmd.com/archive/slurm-master/ . Slurm can be downloaded from https://www.schedmd.com/download-slurm/. The changelog for 25.11 can be found here: https://github.com/SchedMD/slurm/blob/master/CHANGELOG/slurm-25.11.md -- Tim Wickberg Chief Technology Officer, SchedMD LLC Commercial Slurm Development and Support

1 0

AuthInfo broken in 25.05.1 ?
by michael＠mayer.cx 27 Oct '25

27 Oct '25

I am using the AuthInfo in both slurm.conf and slurmdbd.conf to point to a different location for the munge socket. This works as expected in slurmdbd, but it does not work for slurmctld. In slurmctld it seems to ignore this setting and try to locate the munge socket at the default location and then fail. When using the same approach in 23.11.11, for example, AuthInfo is working as expected for both slurmctld and slurmdbd. Sample config from slurm.conf and slurmdbd.conf AuthType=auth/munge AuthInfo=socket=/my/non-default/location/of/munge.socket I'd be grateful for any pointer whether this is a genuine bug/regression or not. Many thanks, Michael.

3 3

Possible to require jobs to use NVLink-ed pairs of GPUs?
by Marcus Lauer 27 Oct '25

27 Oct '25

One of our researchers asked whether it was possible to require a job to use NVLink-ed pairs of GPUs. I see that there is a support ticket on the SchedMD site which covers this (https://support.schedmd.com/show_bug.cgi?id=15995) That ticket is a few years old though. Does anyone happen to know whether support for this has been added in newer releases of SLURM? The cluster in question does use "AutoDetect=nvml" in its gres.conf and the output of "slurmd -G" shows that SLURM is aware of the NVLink pairs. I assume the scheduler is trying to use that information. What I want to know is whether there is some way for an end-user to add a constraint (for example) to a job such that it only runs on an NVLink-ed pair of GPUs. I do know that there are other ways to implement this such as requiring jobs to run with even numbers of GPUs, perhaps just on some nodes to allow single GPU jobs to run on the remaining nodes. I'm specifically asking about a flag or setting a user could apply to their jobs. If there is such a thing maybe someone here knows about it. If so I'd love to hear about it. Thanks! -- *Mr. Marcus Lauer* Systems Administrator Penn Engineering University of Pennsylvania https://www.seas.upenn.edu/

1 0

Limit number of allocated GPUs
by Gestió Servidors 23 Oct '25

23 Oct '25

Hello, I have three nodes, serving each one 2 GPUs. I would like to limit (qos??) that a user could user only one GPU from earch server, but user could user simultaneously three GPUs if each GPU belongs to different servers. With this QoS "sacctmgr add qos test-limit-GPUs MaxJobsPerUser=3 MaxTRESPerUser=gres/gpu=1" I can limit to one GPU, but then user can't run other job in a GPU from other server. How must I configure QoS (or other method) to allow more than one job requesting GPUs but never in the same server? Thanks.

3 2

Job remains "PENDING" with reason "QOSMaxGRESPerUser"
by Gestió Servidors 23 Oct '25

23 Oct '25

Hello, I have added a new "qos" with these parameters: sacctmgr add qos test-GPUs MaxJobsPerUser=6 MaxTRESPerUser=gres/gpu=1 MaxSubmitJobsPerUser=25. With it, I only allow 6 running jobs per user, a total of 25 pending+running job per user and only 1 GPU. I have applied this qos directly to a partition in slurm.conf. When a user submits to that partition requesting 2 or more GPUs, job remains "PD" (pending) and notifies "QOSMaxGRESPerUser" in NODELIST column, but I would like to know if it would be possible to direcly reject job and avoid that job remains at queue? For example, if I submit 50 jobs, after number 25 I get message "sbatch: error: Batch job submission failed: Job violates accounting/QOS policy (job submit limit, user's size and/or time limits) sbatch: error: QOSMaxSubmitJobPerUserLimit" 25 times) Thanks.

2 1

dynamic node slurm node list order
by Assmann, Greta Marie 23 Oct '25

23 Oct '25

Hello, we would like to understand how the internal SLURM node list order works. More detailed info: Our setup: We have a Slurm cluster with N dynamic nodes (heterogeneous node types) in a partition and we observe that if all resources are free, jobs always get submitted to one specific node first. This node is also the node that turns up at the top of the list when doing an $ scontrol show nodes . As we do not have a defined node list in slurm.conf as it is done for non-dynamic nodes, we were wondering how the order is set up. Interestingly, when deleting (and unregistering) this node from the cluster and re-registering it again, the node is still at the same position when doing scontrol show nodes. Is there some internal node list order caching or similar? How is the node list order defined ? Thanks , Greta Dr. Greta Assmann Data Analysis and Research Infrastructure OBBA 230 Forschungsstrasse 111 5232 Villigen-PSI email: greta.assmann(a)psi.ch

4 5

Slurm and Slinky events this fall, update events page
by Tim Wickberg 14 Oct '25

14 Oct '25

We'll have a bit more details as conference season quickly approaches this November, but SchedMD staff are presenting at KubeCon NA on Slinky [1]. We'll be manning the Slurm Booth at SC25 [2], as well as hosting the annual Slurm Community Birds-of-a-Feather session [3]. I'll also send a link out to the survey questions for the BoF to the slurm-users list ahead of the conference, and we'll be going into a bit more depth on the answers during the BoF this year. The events page on the SchedMD website has more detail on future events as well: https://www.schedmd.com/events/ A few folks had asked, and apparently we never mentioned this more publicly, but: SchedMD does not plan to hold an in-person SLUG in 2025 or 2026. We are working to bring some of the same content to our YouTube channel [4] as a way to more broadly disseminate some of that same content, starting with the Slurm 25.11 release overview in December. - Tim [1] https://kccncna2025.sched.com/event/27FW5/ [2] The Slurm Booth is #1641. [3] https://sc25.conference-program.com/presentation/?id=bof101&sess=sess471 [4] https://www.youtube.com/SchedMDSlurm -- Tim Wickberg Chief Technology Officer, SchedMD LLC Commercial Slurm Development and Support

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Slurm version 25.05.4 is now available
by Marshall Garey 14 Oct '25

14 Oct '25

We are pleased to announce the availability of Slurm version 25.05.4. This version increases the default number of maximum connections to slurmctld from 50 to 512, fixes a regression added in 25.05.2 that broke compatibility with PMIx v2.x through v3.1.0rc1, and fixes other minor to moderate bugs. The full list of changes are available in the CHANGELOG: 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 Release Management, Support, and Development SchedMD LLC - Commercial Slurm Development and Support

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Preemption Scheduler Tuning Knobs
by Reed Dier 13 Oct '25

13 Oct '25

Hoping someone may be able to help demystify some questions around the scheduler and preemption decisions. I'm trying to help better predict the scheduler behavior as it pertains to preemption to create more predictable scheduling. Version is 24.11.5, OS U22.04 I have a fairly simple lo/hi partition which the same set of nodes are assigned > PartitionName=partition-lo Nodes=foo[00..NN] Default=YES MaxTime=INFINITE OverSubscribe=FORCE:1 State=UP > PartitionName=partition-hi Nodes=foo[00..NN] Default=YES MaxTime=INFINITE OverSubscribe=NO State=UP PreemptMode=OFF And then I have 2 QOSs per partition > Name Priority GraceTime Preempt PreemptMode UsageFactor MaxJobsPU MaxTRESPA MaxJobsPA > ---------------- ---------- ---------- ---------------------- ----------- ----------- --------- ------------- --------- > qos-stateless-lo 1 00:00:00 requeue 1.000000 > qos-stateful-lo 1 00:00:00 suspend 1.000000 NN cpu=NNN NNN > qos-stateful-hi 5 00:00:00 qos-state[ful,less]-lo cluster 1.000000 cpu=NNN > qos-stateless-hi 5 00:00:00 qos-state[ful,less]-lo cluster 1.000000 And the general way that it works out is that stateful jobs will typically spawn stateless jobs. Stateful jobs will get suspended, while stateless jobs will get requeued. And then there are some general guard rails around stateful jobs clogging the queue and preventing stateless jobs from scheduling and creating a deadlock, but thats not the specific issue here. > SchedulerType=sched/backfill > SelectType=select/cons_tres > SelectTypeParameters=CR_CPU_Memory > SchedulerParameters=max_rpc_cnt=500,\ > sched_min_interval=50000,\ > sched_max_job_start=300,\ > batch_sched_delay=6 > PriorityType=priority/multifactor > PreemptType=preempt/qos > PreemptMode=SUSPEND,GANG Workload is rather "high throughput", so a few settings were influenced by that <https://slurm.schedmd.com/high_throughput.html> guide. What I end up seeing is that it can take sometimes, but not always, take a while for lo jobs to be preempted by hi jobs, an example below, but if the mailing list eats images, a link to it here: https://imgur.com/a/7xVFC8a This is a rather low resolution view, as it is just a scraper running on 5 minute increments, but the blue filled area are "hi" jobs running, where the yellow are "lo" jobs running. Second image (dashed lines) are pending jobs for the same partitions. Oddly, this specific instance did not show any preemption events in the slurmctld logs, but users/admins were a bit perplexed as to why this drug on for so long, and without preemption kicking in. I was considering looking deeper into to try to better understand and predict preemption decisions: default_queue_depth partition_job_depth sched_interval sched_min_interval defer Hopefully someone can point me to some nuggets of information around this? Appreciate any pointers, Reed

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About tpology.conf
by ysaiki18＠gmail.com 12 Oct '25

12 Oct '25

Must topology.conf, like slurm.conf, be accessible to all nodes?

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Prolog error causing node to drain
by Ratnasamy, Fritz 11 Oct '25

11 Oct '25

Hi, We have a running slurm cluster and users have been submitting jobs for the past 3 months without any issues. Recently, some nodes jobs are getting drained randomly due to the reason "prolog error" Our slurm.conf has these 2 lines regarding prolog: PrologFlags=Contain,Alloc,X11 Prolog=/slurm_stuff/bin/prolog.d/prolog* Inside the prolog.d folder, there are 2 scripts which run with no errors as far as I can see but is there a way to debug why the nodes are going in draining mode once in a while because of "prolog error"? That seems to happen at random times and on random nodes. From the log file, I can see only this: Oct 06 00:57:43 pgpu008.chicagobooth.edu slurmd[3709622]: slurmd: error: prolog failed: rc:230 output:Successfully started proces> Oct 06 00:57:43 pgpu008.chicagobooth.edu slurmd[3709622]: slurmd: error: [job 20398] prolog failed status=230:0 Oct 06 00:57:43 pgpu008 slurmd[3709622]: slurmd: Job 20398 already killed, do not launch batch job Oct 06 13:06:23 pgpu008 systemd[1]: Stopping Slurm node daemon... Oct 06 13:06:23 pgpu008 slurmd[3709622]: slurmd: Caught SIGTERM. Shutting down. Oct 06 13:06:23 pgpu008 slurmd[3709622]: slurmd: Slurmd shutdown completing Currently, now the job 20398 that is getting killed in the picture above is in the state "Launch failed requeue held" after I resume the node. *Fritz Ratnasamy*Data Scientist Information Technology

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Testing Slurm on FreeBSD – Offering Feedback and Collaboration
by Rikka Göring 07 Oct '25

07 Oct '25

Hello everyone, I’d like to briefly introduce myself and share some good news. I maintain the FreeBSD port of Slurm (sysutils/slurm-wlm) and have just completed the upgrade to the latest release. Alongside this, several FreeBSD-related fixes I had been maintaining locally have now been merged upstream by SchedMD engineers, which is an encouraging step for portability. With the updated port now running reliably on FreeBSD, I can offer: - Regular build and runtime testing of Slurm on FreeBSD, - Feedback on portability patches and non-Linux code paths, - Collaboration with anyone interested in running or experimenting with Slurm on BSD systems. My goal is to help ensure that Slurm remains portable and usable on FreeBSD, and to contribute back testing and fixes where possible. If you’re working on anything that may affect portability, feel free to reach out — I’d be glad to test and provide results from the FreeBSD side. Best regards, Rikka Göring

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