topic Re: Volume usage greater that Size in Array Performance and Data Protection

Volume usage greater that Size

tcrowley96 — Wed, 22 Jun 2016 14:20:45 GMT

How can volume usage be greater than volume size.

Regards

Tim

Re: Volume usage greater that Size

jkincer57 — Thu, 23 Jun 2016 13:11:04 GMT

I had this issue as well.... ended up opening a case with Nimble. They wanted us to follow this VMware article. https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2057513

In the end this didn't help us and we had to storage vmo to a new datastore to reclaim the space.

Re: Volume usage greater that Size

jstinson105 — Thu, 23 Jun 2016 14:13:24 GMT

Maybe Nimble is accounting for metadata? Also, it looks like the data is incompressible in which case trying to apply compression can slightly increase the data usage. I believe I've read (though I can't find it right now) that the LZ4 compression employed by NimbleOS has a worst case inflation of roughly 3% which is what you're seeing. If you do have compression enabled, would it be possible to copy your data to another volume that has it turned off to see if you get the same result?

Re: Volume usage greater that Size

pflammer23 — Mon, 27 Jun 2016 20:22:18 GMT

Hello Tim,

I have seen this before at one of my customers.

Please call support. I believe this is a bug that is fixed in the latest release (currently 3.3).

Please let us know what support said.

Kind Regards,

Pierre

Re: Volume usage greater that Size

tcrowley96 — Tue, 05 Jul 2016 08:06:33 GMT

Responce from support

-------------------------------------

The reason for volume reporting incorrect space usage is, high IO and generation deletions are falling behind and all the space locked up in those deletions generations are being reported in the volume usage.

This is a known issue and the fix for this is addressed in the release NOS 3.X which is still a release candidate and not recommended for production critical environments. However, Nimble support would notify you, upon NOS 3.X getting into general availability.

Re: Volume usage greater that Size

pflammer23 — Tue, 05 Jul 2016 08:09:36 GMT

Thanks for letting us know Tim!