CMS Compute and Storage downtime
On Wednesday afternoon March 4th 2026, the '2550' Data-Center, which hosts the CMS Tier-2, will undergo a planned full power outage, needed for upgrades.
This will affect the following services:
- CMS Front-End (aka 'Login') nodes;
- EOS storage;
- XCache;
- CVMFS;
- Hammer cluster SLURM jobs;
- Analysis Facility will operate in reduced capacity:
- fewer CPUs, RAM and GPUs will be available;
- CVMFS and EOS mounts will not be available;
- XCache will not be usable.
Given the scale of the event, we have scheduled a 'full downtime' for our computing resources.
Users will be able to do some interactive work in the AF and the Community Clusters (other than 'Hammer'), as home-directories and Depot storage are not expected to be affected (they are hosted in the MATH Data-Center), but are strongly advised to not depend on the reliability of any services during the power outage period.
The current plan is to have all machines powered down before the end of day (5pm) on Wed. March 4th, and then have them powered back up by start of business (9am) on Thu. March 5th.
Please - plan your use of the resources accordingly. CMS Support Team