Monday, January 14, 2013

Extending A vSphere Replicated Virtual Disk

I recently had a VM that needed one of its virtual disks extended.  vSphere Replication needed to be disabled for this disk before vCenter would allow this operation.
When reconfiguring replication for this VM/disk, it detected the original/smaller disk:
Duplicate File Found. Do you want to use this file as an initial copy?
If you choose yes, it will try to use this file instead of re-sending the entire virtual disk.  This option didn't work. I think the files are just too different (size) and it doesn't know how to handle it.

If you choose no, you can configure a different datastore, but it won't let you use the same one.  This would leave the original replicated virtual disk out there unnecessarily taking up space.

I ended up manually deleting the original replicated VMDK and had VR resend the virtual disk again.  No big deal this time as it was just Disk 0/C: drive but this could be a real PitA if you need to extend a larger disk.

Lessons learned:

  1. Size your drives properly the first time.
  2. Consider creating a new disk instead of extending an already large virtual disk (30, 40, 50GB+).