Using EL9 Farm Nodes


Red Hat Enterprise Linux 7 and its derivatives ("EL7"), which includes the Farm's CentOS Linux 7 distribution, reached end-of-life in June 2024.  The Farm migrated to AlmaLinux 9 (an "EL9"), and CentOS Linux 7 is no longer generally available on the Farm.  Unlike our regular monthly minor y- and z-stream updates, this is not only a "major" version update, but a skip, from 7 to 9, including changes to system software beyond the scope of this article.  Here, we'd like to outline some JLab-specific differences with the previous configuration of our CentOS Linux 7 nodes.

Filesystem Changes

To better isolate dependencies on CUE filesystems and reduce outages due to maintenance of those systems, we have made a few impactful changes.

/apps removed

The /apps area has been replaced.  To provide better portability of compute jobs, we have moved to CVMFS.  See the related article on modulefile usage.

/site removed

The /site area housed several SciComp utilities.  Those tools (e.g. CacheManager, Jasmine commands, swif2) have been moved to local installs on the EL9 interactive node.  They are not available on compute nodes.  If your ~/.cshrc and ~/.login contain source /site/env/sys_____ directives (as both do by default at JLab), you will see

/site/env/sys_____: No such file or directory

when logging in.  You may either comment-out/remove those directives, or, if you wish them to remain in effect on CUE hosts that mount /site, make them conditional, e.g.

if (-d /site/env) then
  source /site/env/syscshrc
endif

and

if (-d /site/env) then
  source /site/env/syslogin
  source /site/env/sysapps
endif

respectively.

/tmp noexec

This is consistent with other recent SciComp service node deployments.  Please use local scratch (/scratch/$USER interactively and /scratch/slurm/$SLURM_JOB_ID in jobs), which is generally faster and better isolated from system processes.  To help with this for things like container builds on ifarm, we set $TMPDIR accordingly (to /scratch/$USER) at the system-level, for all users.

/farm new cluster-based top-level

Compiling/Building Software

Continue to use the interactive node (ifarm.jlab.org) for building your software.  You may need to rebuild applications that were originally built on EL7.

If you find you need other modules/versions to be supplied, please submit a ServiceNow incident so it can be addressed.

Known Issues

Known issues on EL9 Nodes