Page History

• Your home directory is in weka (/sdf/home/<first letter of your userid>/<your userid>) with 30 GB of space. This space is backed up and is where code, etc., should go. 
• We have group space at /sdf/group/fermi/

• :
  • some directories are under /sdf/data/fermi/, but we provide links into the group directory tree for easier access
  • includes shared software,

• • including conda envs for Fermitools and containers for running rhel6 executables
  • Fermi-supplied user (i.e., on top of your home directory)

• • space.
    • You can find it in /sdf/group/fermi/u/<you>. There is a symlink to it, called "fermi-user", in your home directory for convenience.
    • after gpfs is retired in late 2023, this is where your larger user space will be.
  • group space in /sdf/group/fermi/g/ - a one-time copy has been done of all the gpfs g/ directories, under /nfs/farm/g/glast/g/.
  • all of glast afs has been copied to /sdf/group/fermi/a/
  • the nfs u<xx> partitions were copied to /sdf/group/fermi/n/ (including u52 which contains the GlastRelease rhel6 builds)
• your user/group space on the old clusters

• is not directly accessible from

• s3df 
  • We're still providing additional user space from the old cluster, available on request via the slac-helplist mailing list. It

• • is not

• •  backed up. This space is natively gpfs.  User directories are available under: /gpfs/slac/fermi/fs2/u/<your_dir>

• • .
    • a read-only copy of all user directories on /nfs/farm/g/glast/u was made in mid-January 2024 and can be found at /sdf/data/fermi/gpfs-u/
  • During the transition, read-only mounts of afs and gpfs are available on the interactive nodes (not batch!).
    • afs is just the normal afs path, eg to your home directory (/afs/slac/u/ ...) - you may need to issue "aklog" to get an afs token.
    • gpfs is /fs/gpfs/slac/fermi/fs2/u/ ...
• Scratch space:
  • /sdf/scratch/<username_initial>/<username>: quota 100GB/per user. The space is visible on all interactive and batch nodes. Old data will be purged when overall space is needed, even if your usages is under the quota
  • /lscratch: On each batch node, this is a local space.  It is shared by all users. You are encourage to create your own sub-dir when running your job, and clean up your space (to zero) at the end of your job. Debris left behind by jobs will be purged periodically. The size of the /lscratch are subject to change and please refer to the table in Slurm partition for info about their size.

See Fermitools/Conda Shared Installation at SLAC.  If you do want your own Conda, you shouldn't install it in your home directory due to quota limits; put it in your Fermi-supplied user space. Follow

the S3DF documentation

 instructions to install Conda and set a prefix path for the Conda installation that will put it and any environments you create in your group-provided space. However, you should use a prefix to your personal space, e.g., /sdf/group/fermi/u/$USER/miniconda3, instead of the path in their example.

You can also run a RHEL6 Singularity container (for apps that are not portable to RHEL/Centos7).

See Using RHEL6 Singularity Container.

see Running on SLAC Central Linux.  Note that the actual batch system has changed and we have not updated the doc to reflect that. This is advice on copying data to local scratch, etc.

If you find you cannot submit jobs to the fermi:users repo, ask for access in the #s3df-migration slack channel.

• LSB_JOBID -> SLURM_JOB_ID
• scratch space during job execution:
  • at job start, a directory is automatically created on the scratch of the worker: ${LSCRATCH} = /lscratch/${USER}/slurm_job_id_${SLURM_JOB_ID}
  • once all of a user's jobs on a node are completed/exited, their corresponding LSCRATCH directory on that host is deleted.

You need to specify an account and "repo" on your slurm submissions. The repos allow subdivision of our allocation to different uses. There are 4 repos available under the fermi account. The format is "–-account fermi:<repo>" where repo is one of:

• default (jobs are pre-emptible - if "paying jobs" need slots, pre-emptible jobs will be killed)
• L1
• other-pipelines
• users 

L1 and other-pipelines are restricted to known pipelines. Non-default repos have quality of service (qos) defaulting to normal (non-pre-emptible).

At time of writing, there is no accounting yet. When that is enabled, we'll have to decide how to split up our allocation into the various repos.

S3DF Slurm organizes the different hardware resource type under Slurm partitions. Slurm doesn't have the concept of batch queue. Users can specify the resource their job needs (because, for example a 12-core CPU request can be satisfied by different types of CPUs). The following is an example script that submits a job to Slurm:

#!/bin/bash
#SBATCH --account=fermi:users
##SBATCH --partition=milano
#SBATCH --job-name=my_first_job
#SBATCH --output=output-%j.txt
#SBATCH --error=output-%j.txt
#SBATCH --ntasks=1
#SBATCH --cpus-per-task=2
#SBATCH --mem-per-cpu=4g
#SBATCH --time=0-00:10:00
hostname

Note that the specifying "--gpus a100:1" option is preferred over the specifying "–partition=ampere" (the latter is not needed). If GPU is not requested, you job will not have access to a GPU even if it is landed on an ampere node.