If using esxi6 without patch 2116126, released on May, 14th 2015, you might loose data when deleting snapshots of vm's with large disks.
In my case, at first the backup job seemed to hang for a long time. After cancelling and deleting the snapshot i had two machines (server 2008 / server2012) with massive ntfs errors.
Meanwhile i know, that this can be caused by a problem in the vm software (see http://kb.vmware.com/kb/2116126 for more information).
If possible i'd suggest to inform BE / Symantec customers before they might run into this problem.
