topic Re: dedup on snapmirror and snapvault in ONTAP Discussions

dedup on snapmirror and snapvault

Thu, 05 Jun 2025 07:27:00 GMT

How does dedup work out for snapvaulted and snapmirrored data ? Primary (source) and Secondary (destination) effect ?

Re: dedup on snapmirror and snapvault

calvarez — Fri, 19 Jun 2009 18:02:45 GMT

Dedupe works differently within Volume SnapMirror and SnapVault.

In the case of Volume SnapMirror, deduplicated data within the volume is transferred in a deduplicated state resulting in a reduction in network bandwidth utilization, as well as the fact that the destination will inherit the deduplication properties from the primary storage.

The SnapVault approach is different. Following the baseline transfer, SnapVault will only transfer changed blocks to the destination resulting in very thin data transfers. Deduplicated data that is transferred with SnapVault is not deduplicated, but can be deduplicated at the destination site. A SnapVault solution that can yield good savings is when SnapVault is used to transfer data from multiple qtrees from multiple volumes, and even different systems, to a single destination which can be deduplicated.

These are the highlights. Please refer to the deduplication Deployment and Implementation Guide for additional benefits and features, as well as best practices.

Re: dedup on snapmirror and snapvault

support — Mon, 22 Jun 2009 14:33:11 GMT

Has bug ID 340685 been addressed already in regards to using Dedup with Snapvault?

Re: dedup on snapmirror and snapvault

radek_kubka — Mon, 22 Jun 2009 15:27:55 GMT

Ed,

Out of my curiosity I just looked at that bug description on NOW - it doesn't seem to have anything to do with de-dupe.

Did you mean something else?

Regards,
Radek

Re: dedup on snapmirror and snapvault

support — Mon, 22 Jun 2009 15:32:37 GMT

To properly take advantage of dedup - it was recommended to run 7.3.1 - which has this bug when using NFS volumes in snapvault. I was hoping that this bug would be addressed soon so that we can upgrade to 7.3.1 and start using dedup.

Re: dedup on snapmirror and snapvault

radek_kubka — Mon, 22 Jun 2009 15:46:03 GMT

OK, hold on a minute - the description says:

"When the Primary is a release prior to 7.3.1 an initialize/update comprising such files with bad atimes to a 7.3.1 Secondary may fail.

This problem does not occur when the Primary and Secondary both are 7.3.1."

So why just not update both ends to 7.3.1?

Regards,
Radek

Re: dedup on snapmirror and snapvault

support — Tue, 23 Jun 2009 14:52:19 GMT

Our concern was that we wanted to run 7.3.1 on our less critical snapvault destination filer first and start looking at dedup - then upgrade our production cluster as well. This bug is our current show stopper. We would love to see dedup in action.

Thanks.

Re: dedup on snapmirror and snapvault

amiller_1 — Fri, 26 Jun 2009 21:59:04 GMT

Do note as well that until 7.3.1 there's a difference between volume level SnapMirror and qtree level SnapMirror (with 7.3.1+ that's now gone).

(If you think about it, that's essentially the same thing as qtree SnapVault.)