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mdemarcork
1 Copper

VM mount setup for snapshots and clones

We are in the process of taking snapshots and clones of a VM server.  The lun is a RDM in physical mode.   I wanted to confirm the setup to mount the snapshot or clone to a VM mount host.  

For the clone lun:

1.       I need add it to the EMC & ESX storage group.  

2.       Add the clone to the VM mount host as a RDM.

3.       Check maintain lun visibility after mount in RM.

By following these steps I will ensure the VM mount host sees the luns any time we need to un-mount and re-mount the clone.  Please confirm.

For the snapshot:

*Not sure what is needed since the snap cache is in private luns.  What is required so we can mount a snapshot.   

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3 Replies
AranH1
4 Beryllium

Re: VM mount setup for snapshots and clones

For the snapshot you will need to manually create the snapshot device, add it to the ESX storage group, and then add the snapshot to the VM mount host as a pRDM. You will need to set the same option in the RM job to maintain LUN visibility. RM will then create the snapshot sessions and activate the session to the snapshot device.
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mdemarcork
1 Copper

Re: VM mount setup for snapshots and clones

We usually keep 4 sessions in the rotation so anyone could be mounted.   Do we need to create a manual snap device for each session.  

Also in RM you have the ability to delete the snapshot, if this is done for troubleshooting or clean-up reasons what happens to the snap device.  Does it get deleted from the array and you will need to remove the RDM and re-create a new snap device.   Similar question when the snapshots expire in the rotation.

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AranH1
4 Beryllium

Re: VM mount setup for snapshots and clones

You will only need to create one snap device per mount host. A snapshot is only activated against one session at a time, so while you will have 4 sessions in rotation (the actual point-in-time image of the source LUN), you will only be accessing one session at a time and therefore will only need one snapshot.

When you manually create the snapshot for use with a VM mount host I believe that only the session is deleted when deleting the snapshot in the RM console. I thought that was how it worked when I did some testing, but I would test it yourself to be sure.

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