Hi Mathias I can't answer your specific question, so this is more of a comment 🙂
We have a system with 8 x Nvidia A40, where we would like to share each GPU between several jobs (they have 48GB each), eg starting 32 jobs, with 4 on each GPU. I looked into MIG as well, but unfortunately that is not supported by the A40 hardware (only A30 and A100). I have tried MPS, but strangely that works only for the first GPU on each node, so only one of the 8 GPUs in our system can be shared in this way. That is, it used to be like that. A couple of weeks ago, an "all_sharing" flag was introduced for gres.conf, which apparently should make it possible to share all the GPUs with MPS. I haven't tried it yet, but it may be worth a try. It should be possible to configure some GPUs as mps and some as gpu resources. Cheers, Esben https://github.com/SchedMD/slurm/blob/master/doc/man/man5/gres.conf.5 all_sharing To be used on a shared gres. This is the opposite of one_sharing and can be used to allow all sharing gres (gpu) on a node to be used for shared gres (mps). NOTE: If a gres has this flag configured it is global, so all other nodes with that gres will have this flag implied. This flag is not combatible with one_sharing for a specific gres. ________________________________ From: slurm-users <slurm-users-boun...@lists.schedmd.com> on behalf of Matthias Leopold <matthias.leop...@meduniwien.ac.at> Sent: Thursday, January 27, 2022 16:27 To: Slurm User Community List <slurm-users@lists.schedmd.com> Subject: [slurm-users] addressing NVIDIA MIG + non MIG devices in Slurm Hi, we have 2 DGX A100 systems which we would like to use with Slurm. We want to use the MIG feature for _some_ of the GPUs. As I somehow suspected I couldn't find a working setup for this in Slurm yet. I'll describe the configuration variants I tried after creating the MIG instances, it might be a longer read, please bear with me. 1. using slurm-mig-discovery for gres.conf (https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.com%2Fnvidia%2Fhpc%2Fslurm-mig-discovery&data=04%7C01%7Cepf%40novozymes.com%7Ca0989487f14947bd269808d9e1a99cc4%7C43d5f49ee03a4d22a2285684196bb001%7C0%7C0%7C637788940862367005%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=AHN8h8%2FcB4xeC7MFdYgZRG7L62PTiz4OvampC1vWL5Q%3D&reserved=0) - CUDA_VISIBLE_DEVICES: list of indices -> seems to bring a working setup and full flexibility at first, but when taking a closer look the selection of GPU devices is completely unpredictable (output of nvidia-smi inside Slurm job) 2. using "AutoDetect=nvml" in gres.conf (Slurm docs) - CUDA_VISIBLE_DEVICES: MIG format (see https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.nvidia.com%2Fcuda%2Fcuda-c-programming-guide%2Findex.html%23env-vars&data=04%7C01%7Cepf%40novozymes.com%7Ca0989487f14947bd269808d9e1a99cc4%7C43d5f49ee03a4d22a2285684196bb001%7C0%7C0%7C637788940862367005%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ZFXeCQh3%2FLO52zpiOqn7CROjq7wvj8zWRE8mj87P%2Bew%3D&reserved=0) 2.1 converting ALL GPUs to MIG - also a full A100 is converted to a 7g.40gb MIG instance - gres.conf: "AutoDetect=nvml" only - slurm.conf Node Def: naming all MIG types (read from slurmd debug log) -> working setup -> problem: IPC (MPI) between MIG instances not possible, this seems to be a by-design limitation 2.2 converting SOME GPUs to MIG - some A100 are NOT in MIG mode 2.2.1 using "AutoDetect=nvml" only (Variant 1) - slurm.conf Node Def: Gres with and without type -> problem: fatal: _foreach_slurm_conf: Some gpu GRES in slurm.conf have a type while others do not (slurm_gres->gres_cnt_config (26) > tmp_count (21)) 2.2.2 using "AutoDetect=nvml" only (Variant 2) - slurm.conf Node Def: only Gres without type (sum of MIG + non MIG) -> problem: different GPU types can't be requested 2.2.3 using partial "AutoDetect=nvml" - gres.conf: "AutoDetect=nvml" + hardcoding of non MIG GPUs - slurm.conf Node Def: MIG + non MIG Gres types -> produces a "perfect" config according to slurmd debug log -> problem: the sanity-check mode of "AutoDetect=nvml" prevents operation (?) -> Reason=gres/gpu:1g.5gb count too low (0 < 21) [slurm@2022-01-27T11:23:59] 2.2.4 using static gres.conf with NVML generated config - using a gres.conf with NVML generated config where I can define the type for non MIG GPU and also set the UniqueId for MIG instances would be the perfect solution - slurm.conf Node Def: MIG + non MIG Gres types -> problem: it doesn't work -> Parsing error at unrecognized key: UniqueId Thanks for reading this far. Am I missing something? How can MIG and non MIG devices be addressed in a cluster? This setup of having MIG and non MIG devices can't be exotic, since having ONLY MIG devices has severe disadvantages (see 2.1). Thanks again for any advice. Matthias
