topic Re: Volumes reporting over 100% space utilization in Array Performance and Data Protection

Volumes Reporting Over 100% Space Utilization

ryanmus124 — Fri, 28 Feb 2014 17:22:25 GMT

Hello -

I'm experiencing an issue where some volumes that have a lot of churn end up reporting over 100% space utilization. One example is a drive that we are using to store SQL backups. We're running Windows 2008R2, SQL 2008, and Nimble CS260G 1.4.7.0-45626-opt.

Every night we drop copies of our databases onto the T: drive, which is a 100GB fully thin-provisioned volume. This process also deletes any backups that are older than 2 days. When I look at the volume in Windows, we are using 60GB of space. When looking in the Nimble Array, it reports that we are using 172.31 of 100 GB.

I understand that there's no way for 2008R2 to natively give space back to the array, but I don't understand how it can take up more than 100% of the space that it has been given. Has anyone else run into something like this? It's currently not an issue for us but I could see this becoming a problem months/years down the road.

Re: Volumes reporting over 100% space utilization

wen35 — Sun, 02 Mar 2014 23:54:20 GMT

Hi Ryan, This seems a bit odd -AFAIK, we do not allow over values over 100% for quota. Have you filed a support case with us to see what might be wrong?

Thanks.

-wen

Re: Volumes reporting over 100% space utilization

ryanmus124 — Mon, 03 Mar 2014 17:09:00 GMT

I don't believe we've opened a support case yet, I'll go down that route and update this thread with the findings. Thanks Wen!

Re: Volumes reporting over 100% space utilization

marktheblue45 — Mon, 03 Mar 2014 23:14:15 GMT

White space? Thin provisioned?

Re: Volumes reporting over 100% space utilization

marktheblue45 — Mon, 03 Mar 2014 23:17:51 GMT

It will be interesting to see what happens if you clear out the white space using space reclaim action with exi cli or another utility. Granted it shouldn't show above 100GB.

Volumes reporting over 100% space utilization

marktheblue45 — Mon, 03 Mar 2014 23:20:58 GMT

Have a look at the "Reclaim Space Quickly" post. I appreciate this isn't the direct issue but could have some bearing on the diagnostic action a subsequent solution.

Re: Volumes reporting over 100% space utilization

ryanmus124 — Tue, 04 Mar 2014 16:39:48 GMT

Hey Mark -

I did go down that route trying to clear up space. It works as expected on test volumes, but on the volumes reporting over 100% utilization there is only minimal change, it will usually clear up a couple percent the first time that it runs.

I did open a support case as Wen suggested, it turns out this is being actively investigated by the Nimble engineering team. I'll update the thread when I hear back.

Re: Volumes reporting over 100% space utilization

marktheblue45 — Wed, 05 Mar 2014 09:51:44 GMT

Cheers Ryan, an interesting problem.

Re: Volumes reporting over 100% space utilization

ryanmus124 — Wed, 19 Mar 2014 18:52:39 GMT

Update on this. Sounds like this is a known bug. This happens when promoting a replica or snapshot and setting its Quota to 100%, it will act as if it has an unlimited quota. The bug number is 46136 and should be resolved (but not retroactively) in a coming update.

So if you are running into this issue, it sounds like the supported resolution is to create a new volume, migrate the data to it and switch volumes on the host.

I would highly recommend using the 'reclaim space quickly' method (Re: Reclaim space quickly (sdelete alternative)) or sdelete before going down this route, sounds like it's a pretty edge-case scenario.

I'd be happy to provide more details if anyone has requests - thanks all for the input!