UNMAP Clarification

Question

I am in a new environment and new to the Equalogic world and would like a little clarification on reclaiming space n the storage. I'm told that it is OK to go with what VWware vCenter says with regard to space and I can disregard what the Group Manager says. There are a lot of Volumes created in this environment and most are replicated and running the UNMAP command on all these would be quite a task not to mention how long it would take. As far as VMware is concerned our storage looks great, but a s far as the Group Manager is concerned, we have some issues. One of the issues that sticks out at me is the overall free space of the aggregate. Makes me a bit nervous. So, my question is, can we disregard the Manager and just go by vCenter's numbers or do we NEED to run the UNMAP command on all the volumes? The second part of that question is, if we do need to run the UNMAP command on the storage, how often does that need to be done? Any comments or suggestions are welcome. thanks in advance!

Perry

Dev Mgr · Answer

The unmap option gives you space back when you are thin provisioning the volumes (on the Equallogic side) and need some of the space back (e.g. after deleting 1 or more VMs from a specific datastore (volume)).

On the Equallogic side you'd want to have 5% or 100GB free space on each member (whichever is less (so usually 100GB unless you are using relatively small drives)). If a specific volume is low on snapshot reserve, or it's thin provisioned and has reached the alarm threshold, you can adjust the alarm threshold in the volume settings on the space tab by sliding the markers around as needed.

bigpoamah · Answer

The Dell tech i was speaking with last night pretty much said that what was reported in the GUI was just a cosmetic issue and that as long as VMware sees the space that there were no issues.  That's why i'm trying to get some clarification.  Thanks for the reply.

EqualLogic

UNMAP Clarification

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