Snapshot files showed a size of 0 bytes on restart after poweroff

Power off the virtual machine(Centos) when I was creating 100K entries with dsbenchmark test script which triggered snapshots with the config(shard-snapshot-batch-count=100) , and then restart the virtual machine, I found all snapshot files written just before power off showed a size of 0 bytes, finally the datastore recovery failed.

This happened only in virtual machine environment but it was normal in physical host environment