[Berzelius-users] Expansion of Berzelius and related downtimes in April/May

[Henrik Henriksson]

Dear Berzelius users,

As you may be aware of, we are expanding the SuperPOD Berzelius with 34
additional nodes, along with additional storage and networking. More information
on the upgrade can be found on our website [0].

We currently estimate this will require about a week of full downtime, along
with some other smaller windows that should be less disruptive. During the
downtimes we will, among other things, install and integrate the new nodes,
extend storage and upgrade switches. Finally, we will run extensive tests and
benchmarks on the full system.

The exact downtime windows are not decided as of now, but our best estimates
indicate these windows:

- Full stop during week 17, April 24 to April 28. All compute nodes and login
   nodes will be unavailable during the full window, any data stored on Berzelius
   will be unavailable. This window is used for the actual extension.

- During weeks 19 to 22, May 8 to June 2, we will run performance testing,
   stability testing and benchmarking. During this period, we expect the cluster
   to be mostly available, but occasionally fully allocated by tests and
   benchmarking jobs, blocking the queue for other jobs.

Please note that these dates are still *very* preliminary and may change. We
will send out updated information when final dates are decided or if any major
changes occur. Please reach out to us with any questions or comments.

[0] https://nsc.liu.se/2023/01/24/Berzelius-expansion.html

Best regards,
Henrik Henriksson
NSC