Enable Dedupe on existing thin volume (3PAR 8200 running 3.2.2 MU6 + patches)

[adamdb_uk]

Hi,

   we've got a customer 3PAR running 3.2.2.709 + patches. All flash. Currently all volumes being provisioned from a single Raid 6 CPG. All thin. Looking into turning on dedup to gain a bit more space as we've just broached our 80% utilisation. Run some dedup estimates and it looks that we can save around 15-20% per VV if we enable dedupe.

I thought you could enable it on a per VV basis from the Action->Edit->General menu but it seems the option is no longer available. (Dedup just shows 'No' with no option or slider to change).

I assume therefore the only way to change the dedup option is to 'Tune' each volume?

Any advice appreciated.

< Edit :  I've found the following CLI which I believe should convert tpvv to tdvv so I guess I can use this

tunevv usr_cpg MY_CPG -tdvv MY_VV >

thanks.

Ad.

[giladzzz]

Hi

first run

checkvv  -dedup_dryrun

to check your potential savings

and remember dedup is done at CPG level

Regards

give a KUDO if this helps

[adamdb_uk]

yes. I ran dedupe estimates via the GUI which I guess runs the same commands.

[Sheldon Smith]

Deduplication requires the volume's data be re-written, with duplicate data stored in a CPG-common volume. Hence the need to use the tunevv command.

If they can hold off, there are improvements in the dedup processing in 3.3.1. Which would require the volumes be first all tuned back to thin, and then to 3.3.1 dedup.

[adamdb_uk]

ok. thanks for the feedback. Customer is at 3.2.2 and has remained so as it was not recommended to go to 3.3.1 due to stability issues. I'd like to move all my clients to 3.3.1 to get the advantages of compression as well as dedupe. Albeit compression and dedupe together with caveats (avoiding the use of storage level snapshots).

If 3.3.1 is now considered production stable I'll talk to the upgrade team about moving this customer onto it. Nice to hear there are some developments coming. Is there a timeline for the latest update you mention?

Also do we know when the issue of using DeCo volumes with snapshots will be solved. I've got a customer that bought 3PAR specifically to leverage this technology via RMC and aren't too happy that they've been advised not to use it as per advisory

https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-a00038827en_us

thanks.

Ad

[Sheldon Smith]

The recommended HPE 3PAR OS version depends on the particular 3PAR model. For current information, check the latest "Active-Inactive Status of HPE 3PAR OS" document at HPE SPOCK.

For futures, please contact your regional 3PAR Product Manager.

[Sanja1]

@Sheldon Smith can dedupe be enabled for vVOLs on CPG level and how?