Posted: Wed 27 Aug 2014, 12:27pm.
Maintenance work will be being performed on the home (N) and group (G) drive services between 6.30 and 9.00am on Friday 29 August.
The services will be unavailable for two or three short intervals during the maintenance period but we will do our best to keep all disruption to a minimum and will restore access to normal as soon as we can.
UPDATE: 29 Aug 2014 - 9:58am
This morning's maintenance work on home (N) and group (G) drive services has been put on hold temporarily.
The checks we carried out as part of today's upgrade identified what appears to be a minor cosmetic bug with the upgraded software. The software vendors are investigating further and we will decide later this morning whether to proceed with the update.
As a result, there may be one or two short interruptions to file access later today but we will keep any disruption to a minimum and will update this page with details of any changes.
Technical details
Three of the four storage nodes are upgraded to the new version of Nexenta storage software. However, during final testing on a clone of the replicated data volume, we have encountered what appears to be a minor, cosmetic bug with the upgraded software. We have opened a ticket with the software vendor, and will await their response before determining how to proceed.
From the checks we performed, it seems that ABE (CIFS access based enumeration) is not working. This is an important feature for the group volume. ACL controls are working as expected, but without ABE some users can be confused about what they think they can access, even though there is no reduction in the security of the data on the share.
The system continues to run normally, but with reduced redundancy. All preparatory steps to allow for a full reversion to the previous software version were completed correctly, so if necessary we can revert with minimal disruption. Since replication of data to the Pevensey cluster is currently suspended, we will decide on a course of action no later than noon today.
UPDATE: 29 Aug 2014 - 1:08pm
We're still working with the software vendor to decide whether to continue with today's upgrade to the home (N) and group (G) storage services.
The services are available for staff and students as normal during this process but are operating without full backups, so we're working to resolve the issue as soon as possible. If the vendors are able to provide a fix for the problem we identified, we will complete the update later today but otherwise we will fall back to the previous version.
This is likely to mean one or two more interruptions to file access during the day but the breaks in service should only last a few minutes and we will publish a further update as soon as we can.
We've been working with the software vendor to find a fix for the problem we identified with today's upgrade to the home (N) and group (G) drive storage services but have so far been unable to identify a suitable resolution.
We are therefore going to revert to the previous version of the software to ensure the usual backups are in place while we continue to work on finding a more permanent solution.
This is likely to mean there will be one or two short interruptions to file access over the weekend but we will continue to publish updates on progress on this page.
