Product Announcements

SRM will not preserve reservations on failover

Saw a good question a few times in the last few weeks:  Will SRM preserve any reservations, limits, etc. that we've put on VMs when it fails over?

The answer is no, it will not!  Make sure you're failing over into appropriate resource pools if this is something that is important to you.  

The shadow VM will not look identical to the protected VM in this respect, so it's key to have an appropriate set of limits and reservations at the resource pool level into which you are failing over.

And moreover, keep in mind that if you then reprotect and failback… you'll need to set up your per-VM reservations and limits once more because technically it's a new VM we've (re)created on failback.

The moral of the story?  Use resource pools and resource mapping for both failover and failback to make sure your reservations and limits are preserved.

-Ken

***Edit***  My friend and respected colleague at VMware Michael W has pointed out quite rightly that you can manually edit the shadow VM's properties to reflect the required reservations.   This is of course another way to accomplish this if it is important to have per-VM reservations.  I like making sure that the resource pools are mapped correctly to start with though, and only if you need to be very specific, edit the shadow VM.  Keep in mind it's not automatic, you have to do it by hand as it were, and when it creates the shadow on the primary site for a reprotect, you'll need to do it again before failback.