topic Re: _Missing space in Volume in ONTAP Discussions

_Missing space in Volume

karel_heijstek — Thu, 05 Jun 2025 05:31:29 GMT

Hello,

I've a strange problem. Altough, to me it's strange.

One of our customers has a FAS2220. On it a employee created a Vol with a Total Cap. of 2.65TB.

It was used as a NFS store for VMWare to place VM's on it. At this moment there's (almost) nothing stored on it.

Snapshotting is off. There is no fractional reserve.

Still the filers reports this:

VOLUME AVAILABLE

Total Data Space: 2.65 TB Data Space: 1011.24 GB

Snapshot reserve: 0 Byte Snapshot Reserve: 0 Byte

USED

Data Space: 5.42 GB

Snapshot Copies Space: 0 Byte

Total: 5.42 GB

So somehow i'm losing 1.6 TB!

Does somebody where can it be or how I can trace it?

Regards,

Karel

Re: _Missing space in Volume

VIRTUALGEEK2 — Fri, 01 Aug 2014 02:10:57 GMT

what reservation have you got for snapshots?

what raid type are you using?

how large is your raid group?

Re: _Missing space in Volume

aborzenkov — Fri, 01 Aug 2014 02:55:16 GMT

You missing space where? In aggregate? Please, please show output of "df -Ah".

Re: _Missing space in Volume

karel_heijstek — Fri, 01 Aug 2014 07:06:47 GMT

Hi Virtualgeek2 and aborzenkov!

@Virtualgeek:

I have no reservation for snapshots on that volume.

Raid type: RAID_DP

I'm not sure what you mean with your third question but we have 2 aggregates. The aggr on which that vol resides has a Total space of 3.85TB from which 2.84TB is used.

@aborzenkov:

I'm missing space in that particular volume. It has a total space of 265 TB and about 1 TB is available. That means that 1.6 TB is in use, but I have no idea where or what.

df -AH ouput:

Re: _Missing space in Volume

aborzenkov — Fri, 01 Aug 2014 07:18:04 GMT

OK, then please paste output of “df -h volume”, “df -hr volume” and “df -hS volulme for the volume where space is missing. Please, paste text in message, not link images.

Re: _Missing space in Volume

karel_heijstek — Fri, 01 Aug 2014 07:23:04 GMT

OK. I will paste text. Sorry for linking.

Here is the output:

BJZRNAS01> df -h /vol/bjzr_vms

Filesystem total used avail capacity Mounted on

/vol/bjzr_vms/ 2713GB 5177MB 1030GB 62% /vol/bjzr_vms/

/vol/bjzr_vms/.snapshot 0TB 0TB 0TB ---% /vol/bjzr_vms/.snapshot

BJZRNAS01> df -hr /vol/bjzr_vms

Filesystem total used avail reserved Mounted on

/vol/bjzr_vms/ 2713GB 5177MB 1030GB 0MB /vol/bjzr_vms/

/vol/bjzr_vms/.snapshot 0TB 0TB 0TB 0TB /vol/bjzr_vms/.snapshot

BJZRNAS01> df -hS /vol/bjzr_vms

Filesystem used total-saved %total-saved deduplicated %deduplicated compressed %compressed

/vol/bjzr_vms/ 5177MB 2036KB 0% 2036KB 0% 0KB 0%

Re: _Missing space in Volume

VIRTUALGEEK2 — Fri, 01 Aug 2014 07:46:49 GMT

can you please do please do a "vol show" and paste the results for that volume?

Re: _Missing space in Volume

aborzenkov — Fri, 01 Aug 2014 07:48:40 GMT

Which Data ONTAP verion?

Re: _Missing space in Volume

karel_heijstek — Fri, 01 Aug 2014 07:50:33 GMT

NetApp Release 8.1.4 7-Mode

Re: _Missing space in Volume

karel_heijstek — Fri, 01 Aug 2014 07:52:57 GMT

Show is no recognized. Probably you mean vol status?

this is the output:

BJZRNAS01> vol status /vol/bjzr_vms

Volume State Status Options

bjzr_vms online raid_dp, flex nosnap=on, create_ucode=on, convert_ucode=on,

sis guarantee=none, fractional_reserve=0

64-bit

Volume UUID: 85859b3c-4aa8-11e2-a86d-123478563412

Containing aggregate: 'aggr0'

Re: _Missing space in Volume

aborzenkov — Fri, 01 Aug 2014 07:57:04 GMT

You may be hit by deduplication bug; see https://kb.netapp.com/support/index?page=content&id=7010056&locale=en_US for procedure to check metadata consumption.

Re: _Missing space in Volume

karel_heijstek — Fri, 01 Aug 2014 08:37:06 GMT

hi aborzenkov,

I will have a look at it! Sounds interesting!

Thanks!

Re: _Missing space in Volume

karel_heijstek — Mon, 11 Aug 2014 12:16:48 GMT

Hi aborzenkov,

Sorry for the late response. I just want to say that you was right! I told my customer what was possibly the reason, but he wants me to verify it by NetAPP. And guess what? They came up with the same KB article.

Beside the possiblity to just delete the volume they came with another possibility.

I paste what they wrote so that it may help somebody else out there!

***

The ‘sis start -s <vol> command discussed in the KB is resource-intensive. To avoid the performance hit,

you can just reset the sis process for the volume. That will clear out all metadata and allow the

fingerprint database to start fresh manually. It will not eliminate the deduplication that has already

been performed.

Stop deduplication for the volume if it is active or queued. Afterward, it can be restarted:

filer> sis stop -a /vol/volume_name

The sis reset command:

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

filer> priv set diag

filer*> sis reset /vol/volume_name

filer> priv set admin

The ‘sis reset’ commands should run in a matter of seconds, a minute at worst.

*Note*: ‘sis reset’ is interactive and will ask some confirmation questions.

This will delete all the volume’s metadata in the volume and aggregate, but will not affect the

currently deduplicated data. However, it will require a rebuild of the tables from scratch.

*****

Thanks for your help!

Regards,

Karel