topic Re: Cleaning up A-SIS space on an Aggregate in ONTAP Discussions

Cleaning up A-SIS space on an Aggregate

MTWALKER80 — Thu, 05 Jun 2025 05:44:26 GMT

Hi There,

I've been looking around for an answer to this question and even have a case open with Netapp.

We have a aggregate that currently has

Total space WAFL reserve Snap reserve Usable space BSR NVLOG A-SIS Smtape

2341005312KB 234100520KB 0KB 2106904792KB 0KB 487269460KB 0KB

We've been looking at expanding a volume on this aggregate that used to have dedupe enabled, but it's now been disabled.

State Status Progress

Disabled Idle Idle for 2627:03:40

I know that we'll probably will need to run sis undo, but will this clear the A-SIS or is there another process needed to do this.

We no longer require the dedupe information for any volume on this aggregate so the fingerprint database can be removed.

Thanks for the help.

Re: Cleaning up A-SIS space on an Aggregate

jasonpugsley — Tue, 04 Feb 2014 23:55:20 GMT

Unless the volume is at the dedupe limit you can just go ahead and resize the volume. There is no need to undo the existing dedupe data unless it's at the dedupe limit or you think your read performance for that volume has been degraded by deduplication. And yes, sis undo will clear the asis data but have a look for any open BURTs against the release of ONTAP you're running - there have been some buggy versions. Oh, and make sure there is sufficient room in the aggregate before running sis undo for that volume. You'll have to look at the documentation for you specific version of ONTAP as many restrictions are removed and limits increased in newer versions.

Jason

Re: Cleaning up A-SIS space on an Aggregate

keitha — Wed, 05 Feb 2014 14:34:19 GMT

Another option you may consider is rerun ASIS on the volume with the -s switch. This will start dedupe fresh and rebuild the database. If the database is large it may contain a large number of stale fingerprints and rerunning dedupe from scratch will free up a bunch of this space. Just be sure you have the free space and the cpu cycles to have dedupe run for a while as this will be a complete scan and may take a while.

Keith

Re: Cleaning up A-SIS space on an Aggregate

AMANSINGH13 — Sun, 23 Feb 2014 01:08:12 GMT

Had same issue and was head scratching where is space is..

Aggregate 'aggr1'

Total space WAFL reserve Snap reserve Usable space BSR NVLOG A-SIS Smtape

1857GB 185GB 0GB 1672GB 0GB 806GB 0GB

sis start -s did it.