Help with DR storage.

[BearHuntr]

We have a Production ESX environment in our primary datacenter and a DR ESX environment in our DR datacenter and we are using EMC Clariion SANs at both locations. Several production LUNs are mirrored to the DR site using Mirrorview in an asynchronous method. One of the LUNs in particular is devoted to VM Templates and it has no powered on machines so it rarely has anything to synchronize. We do use Site Recovery Manager, but for the purposes of what I am trying to do, it is really not pertinent.

Here is what I am trying to do: I want to temporarily connect the mirrored Template LUN to the DR ESX environment so that I can build a new VM from one of the templates at the DR site.

I have tried fracturing the mirror and connecting the DR LUN to the DR ESX host, and it shows up in storage management, but the VMFS volume is not present. If I try to add storage, it looks like the disk is empty and the wizard fails to complete.

I have tried creating a snapshot of the mirrored LUN and connecting the snapshot to the DR ESX host, and it also shows up in storage management, but the VMFS volume is also not present. If I try to add storage, it formats the disk.

Any ideas???

[chilow]

You will need to update the EnableResignature and DisallowSnapshotLUN settings on the ESX server. ESX4.x KB...[http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1011387] . There is some info in the kb about ESX3.x......For ESX 3.x check out http://www.vmware.com/pdf/vi3_301_201_san_cfg.pdf and search for VMFS Volume Resignaturing, there is updated information on PDF pages 135-137

[BearHuntr]

My DR ESX is version 4, and I tried the esxcfg-volume -l command and it says there is no filesystem on the device. Do I need to be in a specific directory?

[AndreTheGiant]

See this KB:

http://kb.vmware.com/kb/1011387 - ESX 4.x handling of LUNs detected as snapshot

Andre

[BearHuntr]

I've gone over this KB several times, and it is not helping my situation. When I try to add storage through the GUI, I am not given any mount options or any VMFS label, it just wants to delete the contents of the LUN. When I try the command line with the esxcfg-volume -l command, it says there is no filesystem on the device. I cannot find the UUID anywhere. The Snapview snapshot is Active in Navisphere and I see it when I rescan the HBAs, plus when I look at the Fibre Channel Disk device I can see that the primary partition is VMFS. This is all very confusing!

[raadek]

Hi,

As usual, storage is the key

No, seriously - did you try to resolve this with your EMC support and/or EMC gurus? Sadly I am not one of them & can only hazard a guess this may be due to snapshot being read-only? (typically I use word 'clone' for writeable snapshots)

Regards,

Radek

[BearHuntr]

So, I was getting extremely frustrated and decided to approach this from a different angle. I tried connecting another mirrored LUN using a Snapview snapshot and that worked perfectly. It seemed that something was wrong with the original LUN that I was working with. I tried deleting the mirror completely and set it back up from scratch, but that yielded the same results where I couldn't add the datastore properly. So I ended up creating a brand new Templates LUN on the Primary SAN and I migrated my templates over to that new LUN and then set that up as a mirror. This one worked!

The only thing that I can think of as to why this was happening is that the original LUN was quite old and had gone through many vmware upgrades over the years. Maybe the VMFS version was older? What sucks is that now I'm going to have to test all the mirrored LUNs to make sure that they all work.