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Cleaning up A-SIS space on an Aggregate

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

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

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

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.