Disaster Recover Issue

[Sheldon_Edwards]

Hello,

We are in the initial stages of our VMWare implementation and came across a problem in our Disaster Recovery Simulation. We have two datacentres with a SANS in each using SAN based replciation. We have a VMWare cluster in each site connected to the SANS. We create a VM on a lun that was being replicated and assigned it a RAW LUN which was also being replicated. We shutdown the VM, removed it from the inventory in site A. On the SANS, we reversed the mirror making the LUNS active in site B. We assigned the LUNS to the ESX hosts in site B. A sacn on the fibre cards showed the LUNS. When we created the storage on the ESX host in site B, it formatted the LUN.

The ESX host detected the LUN had a vmfs file system on it but it still formatted the LUN. How do we stop the ESX host in site B from formatting the LUNS?

[Texiwill · Accepted solution]

Hello,

You have several issues going on.

1) Your LUNs appeared to ESX but they may not have had a VMFS on them. When you see the LUNs with a Rescan and they have a VMFS on them they will appear within the system as having a VMFS and will not allow you to add them.

Be sure your advanced option LVM.EnableResignature is set to 1.

2) You should not need to 'create the storage' on Site B. The storage should exist already if the mirror was completed. All existing VMFS should appear magically as long as you enable resignature.

Be sure the mirror/replication has finished before progressing.

What SAN are you using? What replication software?

Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education. As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

[Sheldon_Edwards]

Setting LVM.EnableResignature to 1 did the job. It was set to 0 on all ESX hosts

Thanks

[kingsfan01]

Hi Edward,

Quick question for you... is there any advantage/disadvantage to enabling the resignature option if not using SAN based snapshots (yet?). I have a LeftHand iSCSI SAN and have seen the requirement for enabling resignaturing if I want to use snapshots but we have yet to do it. Is this something that can be enabled without causing other issues? We are currently replicating our data with Double-Take as our environment does not yet support SAN to SAN rep.

Thanks!

Tyler