HP StorageWorks XP Fast Recovery Solution administration guide: Windows Server 2003 (B9552-96004, September 2005)

Overview 21
can use the FRS GUI to restore the production volumes from the most
recent data copy or another point-in-time copy on the recovery volumes.
Volume Shadow Copy Service (VSS)
Microsoft’s VSS manages creation and maintenance of shadow copies of
production data for backup and recovery. This service works under the
control of the FRS interface and the Windows OS file system services.
When directed by FRS, VSS coordinates with the writer and hardware
providers to enable shadow copying of production data to the recovery
volumes. The shadow copies contain static copies of all files, such as
databases, transaction logs, and checkpoint files. Because VSS coordinates
copying, the files are copied in a defined state.
Copy terminology
Understanding how Microsoft VSS terminology corresponds to standard IT
industry terms for data copying makes it easier to understand what VSS
does. The following paragraphs explain the terminology.
Microsoft generally refers to a VSS copy as a “volume shadow copy.”
When created using HP FRS and HWP, this type of copy is a static replica
of an original volume’s contents. It is keyed with a GUID to allow
identification of the parts of a shadow copy set that span multiple volumes.
Microsoft also refers to a VSS copy as a “plex,” commonly known in the IT
industry as a “split mirror.”
The shadow copies made on the XP array using VSS, FRS, and HWP are
always static, point-in-time copies.