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Scheduled Downtime

Next Scheduled downtime

Migration to new storage

Thursday 17th January 2019, 9.00am to 1.00 pm. This downtime is reconfigure systems to use the new ARC storage.  All ARC systems will be unavailable during the reconfiguration work.  More information about the storage migration is available here.

Why does ARC require scheduled downtime?

Scheduling regular downtime for the ARC facility enables essential maintenance to be undertaken on the ARC systems that cannot be done while the clusters are in active use. Regular maintenance also reduces the chances that unscheduled downtime occurs.

What to expect during scheduled downtime

Access to ARC Systems

During the downtime period, you will not be able to log in to ARC systems (or systems run by ARC) and if you are already logged in, you will be logged out. This does of course mean you will not have access to your files so we advise you make a local copy of any files you require during the scheduled downtime.

Queues on the ARC Systems

Prior to the downtime, maintenance reservations are placed on all compute nodes across the ARC systems to ensure that the compute nodes are not running any jobs during the downtime. In the lead up to the downtime, you may observe either your jobs being placed on hold, or your jobs not starting despite compute nodes being free, as each system drains the jobs from the compute nodes.

During the downtime period, the contents of the queues will remain preserved to the best of our abilities. If you asked for the walltime of your job to be extended so that it is still running during the downtime period, we will do our best to keep the job running but it is likely that we will need to kill the job to perform our maintenance work.

At the end of the downtime period, the maintenance reservations on the compute nodes are removed and the jobs will start running again.

How frequently will downtime be scheduled?

ARC is aiming to have scheduled downtime once per quarter. These dates are tentative (see the downtime schedule below) and if the schedule conflicts with your essential work or training course, please contact us as soon as possible at support@arc.ox.ac.uk.

Aside from the downtime schedule below, it may be necessary schedule downtime at short notice to resolve more urgent issues. In such cases, annoucenments will be made to ARC users with as much notice as is possible.