HP 3PAR Application Software Suite for Microsoft Exchange - Manual (Page 11)

Microsoft Volume Shadow Copy Service
Microsoft includes VSS (Volume Shadow Copy Service) in Windows to simplify the enterprise’s
storage environment. It provides a framework for creating a point-in-time copy of either a single
volume or multiple volumes.
Microsoft Windows Server VSS works with the VSS-aware applications that are in use to determine
when a volume shadow copy (snapshot) can be made. (A snapshot is a virtual copy: a copy of
some data set, for example, a disk volume, at a point in time.) VSS then communicates with the
operating system and applications and freezes I/O to the storage system to allow snapshot creation
(without the freeze function, data could become corrupted when the snapshot is taken because the
system might be in the middle of a task). Meanwhile, applications continue to run uninterrupted.
The original volume continues to change as the process continues, but the shadow copy of the
volume remains constant. VSS also gives permission to the backup application to access the volume
and back it up in its frozen state. The shadow copy volume is then used for the actual backup.
After VSS saves the shadow copy volume on the backup device, it deletes the shadow copy.
VSS coordinates between Requestors (backup applications such as Recovery Manager), Writers,
and Providers (components that create the shadow copies).
Table 1 VSS Components
VSS Component Description VSS Component
The requestor is backup software that initiates the creation
of the shadow copy. Requestor
The writer is any application software that participates in
the shadow copy process and whose files and data are
included in the process. Writer
The provider is the storage technology that does the actual
shadow copy. Provider
Supported VSS Components
VSS components currently supported by 3PAR VSS Provider for Microsoft Windows include:
•
Requestor
Recovery Manager ◦
◦ Symantec NetBackup for Microsoft Windows
◦ HP Data Protector for Microsoft Windows
•
Writer - Microsoft Exchange 2007 and 2010
NOTE: For platform-specific release levels, refer to the latest HP 3PAR InForm OS Configuration
Matrix. To obtain a copy of this documentation, go to http://www.hp.com/go/3par/ , navigate
to your product page, click Support for your product, and then click Manuals.
Microsoft Volume Shadow Copy Service 11