SRM EMC & snapview

[dcoz]

Hi Guys,

I am looking at SRM with a CX3-10c.

We currently have a cx3-10c replicating to another cx3-10c using mirroeview/A.

So at this point we have LUNs being presented to the ESX cluster in the protected site which are being replicated using mirrorview/A to the recovery SAN.

These LUNs are part of a single consistency group.

I'm curious about the snapshot that is used for the test failover.

If i create a snapshot of the replicated LUN with the relevant naming convention, and present this snapshot to the recovery cluster.

1. Do i also present the same snapshot to the protected ESX cluster?

2. As far as i'm aware the snapshot only goes active once the test plan is invoked.

Once the test plan has finished, does the snapshot get removed from the storage group as part of the clean up process?

3. Can this snapshot be deleted and a new one created at a later date?

Basically i am just trying to figure out what happens to a snapshot once the test is over, and whether this snap can be deleted, and a newer one created at a later date without issue.

Thanks

DC

[TimOudin]

Although I cannot really help much with MirrorView I can add that the snapshot that needs to be created on the recovery site array will only need to be masked to the recovery ESX servers. For actually executing a Recovery Plan and testing a failback then a snapshot on the original protected would need to be created and masked to the original protected ESX hosts.

IIRC, Mike Laverick has a chapter in his most recent SRM book on the configuration of MirrorView/S for SRM, this might be of use to you!

Not sure of the ramifications of deleting the snapshots...

Cheers

Tim Oudin

[CHogan · Accepted solution]

Hi DC,

Hopefully some of these replies will be helpful.

1. Do i also present the same snapshot to the protected ESX cluster?

Nope - you only need the snapshot created on the recovery site, and presented to the recovery site cluster. There is no requirement to present a snapshot to the protected site (at least not for the purposes of SRM anyway).

2. As far as i'm aware the snapshot only goes active once the test plan is invoked.

Once the test plan has finished, does the snapshot get removed from the storage group as part of the clean up process?

You are correct when you say that the snapshot goes active only during a test failover. The snapshot is permanently in the storage group and does not get removed at the end of the test failover however. What happens is that a snapshot session gets established during a test failover which makes the snapshot active (which makes it visible to the outside world) and after the test failover, the session is removed (not the snapshot) which unpresents the snapshot once again.

So a test failover start and stop and basically creating & deleting snapshot sessions, not the snapshot itself.

3. Can this snapshot be deleted and a new one created at a later date?

I'm pretty sure the answer to this is yes since it is 'inactive' other than when involved in a test failover. I guess the only caveat would be that you would not be able to do test failovers. But I'm sure you know that already.

HTH

Cormac

[dcoz]

Thats great thaks.

In regards to deleting the snapshot. If i delete it, and 2 months down the line recreate it. This should be fine shouldn't it?

Thanks

Douglas

[CHogan]

Hi Douglas,

Other than your inability to do any testfailovers, I can't see any problem with it.

I don't know if there are any supportability statements around a 'requirement' to have a snapshot, but i don't believe there are.

HTH

Cormac

[dcoz]

Hi Guys,

I spoke to vmware and they mentioned that you create a snapshot, and the session is the element that makes sure you are using the latest data.

So from what i can gather you dont delete the snapshot.

Thanks

Dougie