VMware vSphere 4.1 now fully supports application level quiescing through VSS. VMware Data Recovery uses different quiescing mechanisms depending on the guest operating system that you run in your virtual machines
For application consistent quiescing to be available three conditions must be met:
– The UUID attribute must be enabled. This is enabled by default on virtual machines created on ESX 4.1 hosts
– The virtual machine must use only SCSI disks. For example, application-consistent quiescing is not supported for virtual machines with IDE disks. There must as many free SCSI slots in the virtual machine as the number of disks. For example if there are 8 SCSI disks on SCSI adapter 1 there are not enough SCSI slots free to perform application quiescing.
– The virtual machine must not use dynamic disks
