topic Re: is it necessary to schedule efficiency scan? in ONTAP Discussions

is it necessary to schedule efficiency scan?

FelixZhou — Wed, 04 Jun 2025 10:36:09 GMT

we are on low efficiency ratio for our AFF800 cluster on ONTAP 9.7P6, online deduplication, compression and compaction enabled.

when I ran "vol efficienty show", it seems all volumes are all idle and never ran efficiency scan.

Is it normal since online does everything or we have to schedule scan manually?

when I kick off one scan for testing, the warning message says the scan may take long time and impact the performance.

is that a good idea to run manual scans?

Please share your experience. thanks.

Re: is it necessary to schedule efficiency scan?

paul_stejskal — Fri, 05 Feb 2021 22:52:37 GMT

If you want more space savings, you can definitely do so. If the inline efficiencies are drawing plenty of space savings then you should be fine.

Generally deduplication is more impactful on hard drives. Since you have an AFF, CPU cycles will be shared as a background task with frontend workloads. All spare CPU cycles will be used, so CPU will probably be 100% busy. This is expected as dedupe wants to finish as fast as possible.

Re: is it necessary to schedule efficiency scan?

jcolonfzenpr — Mon, 08 Feb 2021 13:31:53 GMT

Storage efficiency gains also depends on the type of data. Have many customers with large dataset with little space-saving because the type of files are already compresed (docx, jpeg, mpg4, etc..).

Also configuring lun space-allocation have better results on SAN environments.

Tips:

https://ranchh.wordpress.com/2020/06/13/netapp-aff-storage-efficiency-field-tips/amp/

Good luck 👍