[Solved] Saga file system performance issue

We’re aware of ongoing issues with the file system performance on Saga and are investigating the cause. This also affects logging in to Saga, where the terminal will hang waiting for a prompt.

Updates will be provided in this post as soon as we have more information to share.

Sorry for the inconvenience.

Update 2021-07-15, 16:33: The issue was identified as a faulty connection between the storage server and the cluster. Performance should be back to normal, but we will monitor the system a bit more before declaring it healthy.
Update 2021-07-14, 15:00: We’ve discovered some faulty drives that are currently being swapped. We hope that the performance will improve once these are in production again.
Update 2021-07-13, 10:03: The file system is a bit more stable now, but we’re still looking into the cause for the degraded performance.

[DONE] Saga Maintenance Stop 23–24 June

[2021-06-25 08:45] The maintenance stop is now over, and Saga is back in full production. There is a new version of Slurm (20.11.7), and storage on /cluster has been reorganised. This should be largely invisible, except that we will simplify the dusage command output to only show one set of quotas (pool 1).

[2021-06-25 08:15] Part of the file system reorganisation took longer than anticipated, but we will start putting Saga back into production now.

[2021-06-23 12:00] The maintenance has now started.

[UPDATE: The correct dates are June 23–24, not July]

There will be a maintenance stop of Saga starting June 23 at 12:00. The stop is planned to last until late June 24.

During the stop, the queue system Slurm will be upgraded to the latest version, and the /cluster file system storage will be reorganised so all user files will be in one storage pool. This will simplify disk quotas.

All compute nodes and login nodes will be shut down during this time, and no jobs will be running during this period. Submitted jobs estimated to run into the downtime reservation will be held in queue.

Slow file system on Saga

We’re experiencing very slow file system on Saga at the moment and are working on identifying the cause.

Update 13:09: The file system is much more responsive now, but we’re still seeing that logins are hanging for ~30 seconds before getting access to the file system. This is being investigated further.

Updates will be provided once we have more information.

Sorry about the inconvenience.

New compute nodes on Saga

Today, Saga has been extended with 120 new compute nodes, increasing the total number of CPUs on the cluster from 9824 to 16064.

The new nodes have been added to the normal partition. They are identical to the old compute nodes in the partition, except that they have 52 CPU cores instead of 40.

We hope this extension will reduce the wait time for normal jobs on Saga.

Saga Maintenenace Downtime 18th-19th February 2021

Dear Saga user. We need to schedule a small downtime of Saga from Thursday 18th February 2021 starting at 08:00, until Friday 19th February 2021, ending at 16:00. If maintenance is finished earlier, we will also open up the machine earlier.

During the maintenance, we will continue the work we started in early december and connect the new storage expansion to the system, and make it available for general use. This will give us several Petabyte extra for project storage and other usage..

We apologize for the inconvenience

[RESOLVED] Saga downtime. 7th December-11th December. Adding 4PB storage.

As previously announced, Saga will be down in the coming week, from 7th December 08:00 until 11th December 16:00.

The downtime is allocated for expanding the storage. When we come back we will have ca 4 Petabyte in addition to the already existing 1 PetaByte.

Update: Saga is back online and running jobs again. The new storage is not online yet, but all the hardware has been mounted.