I noticed one important difference between those VMFS-versions and that is the treatment of deleted files.
- ESXi 5.1 and earlier: if a flat.vmdk gets deleted through a user-mistake or problem with a Datastorebrowseroperation there is a quite good chance to recover the file with little effort
- ESXi 5.5 and later: to recover a deleted flat.vmdk it is now required to search the raw-volume - recovering thin provisioned vmdks like that is next to impossible unless you are way more skilled than me.
Problem:
moving vmdks from one datastore to another has become more dangerous - if the action fails for whatever reasons the result can be that both the original and the copy are no longer recoverable.
Just had a case recently: user uses datastorebrowser to move a vmdk from one datastore to another. After half a day the operation finished with success message: actually datastorebrowser showed just the descriptor on the target datastore - the flat.vmdk was lost.It was pure luck that I could recover the flat.vmdk after 2 days of scanning - lucky conditions : empty target datastore plus thick provisioning.
Tip:
- avoid moving vmdks with anything else but vmkfstools -i on ESXi 5.5 and later
- be more careful with deleting vmdks on ESXi 5.5 and later
If anybody has useful links to documentation about the changed delete-operation please let me know - I am not aware of any docs that even mention a change at all.
Ulli