Unity Users,
We are pleased to announce Unity is now open for use again following our June 5 through June 10, 2023 maintenance. Thank you for your patience as we performed necessary upgrades and maintenance to keep Unity running smoothly.
We’ve included a copy of the change list below. If you have any questions or encounter any issues, please submit a ticket to hpc@umass.edu.
In addition to the announced changes below, we’re currently resolving a problem with the Mathematica license. We apologize for any inconvenience and hope to have it fixed shortly.
Welcome back!
Change List
Priority Queue Default Time:
We’re reducing the default time on Priority queues to 1 hour. The maximum time remains unchanged. To run jobs longer than one hour, use the “-t” flag to set the time limit to the desired time for your job. The Slurm scheduler is most effective when jobs are scheduled with accurate time limits, so please set the time limit to a realistic limit for your job.
Module Changes
The module hierarchy update will be out of beta and deployed as the default on Unity. Please see here for a description of of the changes. In addition, we will be enabling the module option to require a module version. This makes it much less likely that your workflow breaks unexpectedly if we install a newer version of a module! If previously you loaded a package with “module load ”, you’ll simply need to update that to “module load /”. For example, “module load apptainer” becomes “module load apptainer/1.1.5”. You can view the available versions of a module with “module spider ”.
Goodbye JupyterHub!
We will be decommissioning JupyterHub in favor of supporting Open OnDemand. JupyterLab, RStudio, and Matlab are all available from the Open OnDemand interface. If you have custom conda environments on JupyterHub, they will be available from the JupyterLab interface in Open OnDemand. See here for documentation, and please send us a ticket or join our Unity User Community Slack if you have any questions or difficulties with the transition.
Disabling Hyperthreading
We’re disabling hyperthreading across Unity since it is often detrimental to HPC workloads. This may mean an apparent core count for a node you frequently use may appear different since hyperthreading appears to Slurm as twice the amount of cores. We have updated our documentation to reflect the true number of CPUs on each node.
Scratch
We will be adding a significant amount of storage to our scratch filesystem and deploying the HPC Workspace scratch management software. You will be able to use the HPC Workspace commands to request a temporary (30 day) scratch directory. This is great if you have jobs that require staging large files or that generate a lot of intermediate file data! Please see our documentation for more information. We anticipate the scratch space being fully available a couple of weeks after the maintenance period.
Slurm Update
Our largest upgrade will be moving Slurm from 20.02.7 to 23.02.2. Most users will not notice a difference since the core functionality remains unchanged. However, it makes more recent Slurm features available