Virtual Hardware Upgrade / Snapshot Issue

[Spad]

I have just migrated several VMs from an ESX 3.5 U4 cluster to an ESX 4 cluster and gone through the migration steps to upgrade VMWare Tools & the virtual hardware.

Unbeknownst to me, however, one of the VMs had a number of snapshots and appears to have reverted to one of them following the virtual hardware upgrade, while claiming to be at the latest point in the chain. I'm assuming from a brief look around that there's nothing I can do to fix this and I'm going to have to recover the VM from a backup?

If so then perhaps some kind of "You've got a load of snapshots, if you continue with this hardware upgrade you'll screw your machine beyond repair" warning would probably have been a good idea.

[psreekanth75]

Hi Spad,

Thanks for using our product,

Reverting to snapshot after Virtual hardware upgrade doesn't cause the VM unusable, We support reverting snapshot after virtual hardware upgrade.

Infact If you have done VMware tools & Virtual Hardware upgrade using VMware Update Manager(VUM), by default it takes snapshot(without Virtual machines's memory) before upgrade.

So that in the event of failure, you can rollback upgrade by reverting back to old snapshot.

Please refer upgrade guide http://www.vmware.com/pdf/vsphere4/r40/vsp_40_upgrade_guide.pdf page# 97

and http://www.vmware.com/pdf/vsp_vum_40_admin_guide.pdf page#75 for more details.

Could you please give us more info by answering following questions to isolate the problem and finding the root cause.

Did you migrate VMs by VMotion or Cold migration?

If you have done cold migration, Are your both ESX35U4 host and ESX 4.0 hosts are of same CPU model?

If both machines are not of same CPU model and you took snapshot with VM's Memory(default option "Snapshot the virtual Machines' memory")

Then reverting to that snapshot makes VM unusable.

Regards

Sreekanth

[tscheez]

I had the same thing happen to me with one of our VM's

The VM had snapshots and after I performed the "Upgrade Virtual Hardware" the VM had reverted back to a very old version. I definately was not try to revert back and the log for the machine does not show that a revert to snapshot was initiated. The only thing that I can figure is that it was the upgrade of the virtual hardware.