Sunday, May 27, 2012

Hot migration and cloning fails on vmfs 2 , 3 and on ESX(i) 4.x

Issue - unable to do hot sVMotion or hot cloning from one or two datastores.
“File is larger than the maximum size supported by datastore  VM/vm.vmdk”

Reason -
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003565
VM provisioned size: 259GB
used (thin) : 121GB
source datastore size : 1TB with 1mb block.
Destination datastore size: 2TB with 8mb block size.
The hot migration/cloning will not be successful since the bottleneck for any disk size which is being transferred during migration/cloning with any VM will be 1MB but the VM's provisioned size being more than 256GB it should be transferred with the block size of 2MB however it conflicts with the 1MB blocksize of the bottleneck of the datastore and thus it will be failed to migrte/clone while it is powered on.