|This chapter excerpt from Inside Windows Storage, by Dilip C. Naik is printed with permission from Addison-Wesley/Prentice Hall,|
Microsoft offers a version of Windows NT that is sometimes referred to as "Embedded NT" and more often as the Server Appliance Kit, or SAK. This offering is based on Windows 2000, which does not have a volume shadow copy service. For the benefit of original equipment manufacturers that use the SAK to build NAS devices, Microsoft has licensed a snapshot solution and included it in the SAK. This snapshot product is the Persistent Storage Manager (PSM) from Columbia Data Products. This section provides a quick overview of PSM architecture and functionality.
PSM architecture is shown in Figure 5.9. PSM has a user mode component that facilitates snapshot management, including initiation and scheduling of snapshot creation. The snapshots are created via the services of the PSM filter driver that is layered over the disk class driver as shown in Figure 5.9.
PSM offers the ability to create multiple snapshots and manage them. Snapshots can be created according to a schedule, and older snapshots may be saved or written over. One can also "mount" the older snapshots and use them for backup or other purposes. Each snapshot has a date and timestamp associated with it.
WINDOWS BACKUP AND RESTORE TECHNOLOGIES
Tip #1: Reasons for backup and restore
Tip #2: Backup problems
Tip #3: Backup classifications
Tip #4: Windows 2000 backup utility
Tip #5: Techniques to create a volume snapshot
Tip #6: XP and Windows 2003 volume shadow copy service
Tip #7: Windows-powered NAS devices and snapshots
Tip #8: Network Data Management Protocol
Tip #9: Practical implications
Tip #10: Summary
About the author: Dilip C. Naik has more than twelve years of experience in various roles at Microsoft, including software engineer, program manager, and technical evangelist. His contributions include writing CIFS/SMB code, CIFS-related RFCs, code and documentation for the Windows NT Installable File System Kit, as well as Windows Management Instrumentation (WMI) and performance/management (including storage management) features for the Windows platform. Dilip has also represented Microsoft on a number of industry standards organizations.
This was first published in April 2005