How to free "Temporary Deduplication" space?

[zamo2k]

Hello,

we have a 8-node FASxxxx cluster with ONTAP 9.7P5.

One thick-provisioned volume had snapshots and deduplication set up.

The command

volume show-footprint

shows a "Temporary Deduplication" quota which goes over the size planned for that volume. I thus disabled deduplication (which benefits where lower than this temporary quota) but "Temporary Deduplication" is still there...

I read that this temporary quota may get "trapped" into snapshots, so I waited until snapshots became newer than the date I removed deduplication... but still "Temporary Deduplication" is there wasting 1,4TB of space.

How can I delete this useless temporary quota?

Thank you in advance.

[RossC · Accepted solution]

Hi @zamo2k 

Actually, likely kicking off another deduplication process would have helped reduce that dedup change log (temporary deduplication space). 

Have a review of https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/How_does_the_deduplication_changelog_work  and https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Systems/FAS_Systems/How_to_justify_volume_metadata_footprint_in_ONTAP_9%3F 

Hope this helps.

[zamo2k]

Hello RossC,

thank you very much for your hint!
Starting from it I discovered that actually re-running dedup solves a known issue: https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/Volume_efficiency_policy_cannot_be_modified_and_volume_cannot_be_promo...

Thank you again!

Regards