VMware ESX backup of a virtual machine with Microsoft iSCSI LUNs attached to the guest operating system fails with the error "Snapshot creation failed: Could not quiesce file system"
V-79-57344-38220 - Backup of the virtual machine 'Guest VM Name' failed. VMware VCB framework reported the following error
Error: Other error encountered: Snapshot creation failed: Could not quiesce file system.
Note: The following solution should only be used for virtual machines which are using the BE VSS Provider (Backup Exec 2010 and later) for Backup. Previous versions of Backup Exec (12.0/12.5) used VCB which is dependent on the file sync driver to flush writes after snapshots, so to uninstall the file sync driver may cause more errors. All writes are successfully flushed by the BE VSS Provider, so the file sync driver is not affected and can be uninstalled.
To disable the VSS driver on the guest operating system, uninstall the VMware tools and reinstall them using the custom installation. On the selected options, do not install the Filesystem Sync Driver and Volume Shadow Copy Services Support.