This article applies to:
- Product edition: Phoenix
A thin disk is restored as a thick disk in the following scenarios:
- At the time of backup, CBT of the source VM was disabled.
- Source VM was on NFS datastore during backup - For NFS datastore, Phoenix cannot perform a * query to find the allocated data blocks. Hence, the Phoenix VMware Agent does not detect the sparse block and backs up the sparse block as zero data block. Therefore, the thin disk is converted into a thick disk during restore.
- At the time of backup, there was no sparse block present on the disk - Phoenix VMware agent does not change the disk type explicitly, but the change is from VMware when there is no sparse block on the disk of the restored VM.
VMware reference article: https://kb.vmware.com/s/article/2077787