Windows Server System State
Comet Backup integrates with Windows Server System State to support backing up System State .vhd files using the wbadmin technology. This feature is only available on certain versions of Windows Server with the "Server Backup Role" feature enabled.
A Windows Server System State backup may include Active Directory, boot files, the COM+ registration, the system Registry hive, and/or other system files.
A local path must be used for spooling temporary data. Spooled temporary data will be removed once the backup job completes. The selected path
- must be a bare root drive, and
- must support VSS, and
- must have at minimum 10GB free space, and
- on Server 2008 and Server 2008 R2, must not reside on a "critical" volume
- You can work around this issue by applying the registry change in Microsoft KB944530.
- must appear to Windows as fixed, not removable - regardless of whether it is physically an internal or external drive
- You can work around this issue for a removable drive by sharing a folder on the drive, and setting its UNC path as the spool directory.
For more information about Windows Server System State backups, please see
- Backing Up System State Data https://technet.microsoft.com/en-us/library/cc938537.aspx
- Wbadmin https://technet.microsoft.com/en-us/library/cc742124(v=ws.11).aspx
Restoring
Once you restore the .vhd file with Comet, you can use the wbadmin start systemstaterecovery command to apply a System State .vhd backup to an installed copy of Windows Server.
Alternative ways of backing up System State
Note that because wbadmin is used, spool space is required. As an alternative, you can back up System State by using the "Application-Aware Writer" Protected Item type. This produces a similar result, but
- no spool space is required; and
- the files are not collected in a
.vhdfile. This may produce better deduplication at the expense of missing bootloader files.