system news

The ordinary login node of Abisko is now online again running Xenial with a similar setup as the one used on Kebnekaise.

There is one other user visible change and that is that the Abisko login node has gotten a new ssh host key.

Most of the ssh clients will complain about this if they have saved the old key.

A message looking something like the following will be seen (this is from a linux ssh session and might be different if using putty or wome other tool):

Abisko is now back in production after the extended maintenance.

Unfortunately a unexpected problem with the upgrade of SLURM caused all pending jobs to be discarded.

We are therefor allowing jobs to be submitted to the old (Precise) part of Abisko for one more week (until April 28th). After that only jobs submitted from the Xenial (abisko-x.hpc2n.umu.se) node will be accepted into the queue.

The system has also been "split" in two halves, one half running Precise the old way, and one half running Xenial and thus only usable from abisko-x.hpc2n.umu.se.

Kebnekaise is now finally back in production after the somewhat delayed maintenance.

Main changes are an updated SLURM version and a new Lustre file system driver version.

On Wednesday April 19th we have a maintenance window from 08:00 to 21:00 to change some Lustre configuration and update Slurm on Abisko.

This affects the /pfs/nobackup filesystem on all batch and login nodes on both Kebnekaise and Abisko.

We must therefore drain the batch nodes of jobs. This means that there will be gaps which can be filled by short jobs during the days before the 19th.

Please do submit short jobs to fill those gaps.

During April we will be upgrading Abisko from Ubuntu Precise to Ubuntu Xenial.

This upgrade will make the environment on Abisko match the one already in use on Kebnekaise.

The reason for doing this is that Ubuntu Precise has End-of-Life on 2017-04-28. (End-of-Life means that after that it will no longer get security updates, bug fixes, etc.)

For more information on the upgrade please see the Abisko: Precise to Xenial migration page.

The bug that has been causing spurious BUS errors for some users have now been indentified and fixed.

It was a bug in the Lustre (/pfs/nobackup) file system that only triggered under very specific conditions and was thus fairly hard to pinpoint.

On Monday March 6 between 20:00 and midnight various core network equipment will be restarted. No jobs will be allowed to start during this maintenance window.

During a routine upgrade of the batch system SLURM on Kebnekaise intended to improve the amount of usable memory on the large memory nodes, we encountered an unexpected malfunction.

This discarded all running and scheduled jobs.

We're working on restoring functionality and will update this system news entry.

Update 2017-02-24 15:42 CET:
The new version of SLURM misbehaves greatly and the commands to interact with it are very slow or not responding at all. You may consider the Kebnekaise cluster down for all practical purposes for now.

We have resolved a long-standing problem with Emacs on the kebnekaise login node. If you had any form of X forwarding enabled invoking emacs would result in a segmentation fault which necessitated a workaround by starting it with the argument -nw.

This is no longer necessary as we have patched the offending library, so now you get a properly working graphical Emacs if you have X forwarding. If you wish to run a textual Emacs in such an environment the argument -nw still exists and works as intended.