Using the Volume Shadow Copy Service

As a new addition to Windows Server 2003, the Volume Shadow Copy Service (VSS) adds the ability to quickly restore data that was deleted from a volume locally or through a network-mapped drive or network file share. Over time, there will be several add-ons to Windows Server 2003 that will extend the functionality of VSS; however, what is built into the operating system already provides a series of data recovery functions. If an organization has available disk capacity, VSS should be enabled as a standard setting for a Client Servicesfocused networking environment.

Configuring Shadow Copies

Enabling shadow copies for a volume can be a simple task. Because shadow copies are created on local disks, shadow copy performance is enhanced if a volume's shadow copy is written to a separate disk. This way, each disk mostly performs either a read or write operation, but not both. The Volume Shadow Copy Service is already installed and is automatically available on NTFS-formatted volumes.

To enable and configure shadow copies, follow these steps:

1.	Log on to the desired server using an account with Local Administrator access.
2.	Click Start, All Programs, Administrative Tools, Computer Management.
3.	In the left pane, if it is not already expanded, double-click Computer Management (local).
4.	Click the plus sign next to Storage.
5.	Select Disk Management.
6.	Right-click Disk Management, select All Tasks, and click Configure Shadow Copies.
7.	On the Shadow Copies page, select a single volume for which you want to enable shadow copies and click Settings.
8.	The Settings page allows you to choose an alternate volume to store the shadow copies. Select the desired volume for the shadow copy.
9.	Configure the maximum amount of disk space that will be allocated to shadow copies.
10.	The default schedule for shadow copies is twice a day at 7:00 a.m. and 12:00 p.m. If this does not meet your business requirements, click the Schedule button and configure a custom schedule.
11.	Click OK to enable shadow copies on that volume and return to the Shadow Copies page.
12.	If necessary, select the next volume and enable shadow copying; otherwise, select the enabled volume and immediately create a shadow copy by clicking the Create Now button.
13.	If necessary, select the next volume and immediately create a shadow copy by clicking the Create Now button.
14.	After the shadow copies are created, click OK to close the Shadow Copies page, close the Computer Management console, and log off the server.

Volume Shadow Copy Best Practices

If volume shadow copies will be enabled on a volume, a few best practices and maintenance tasks should be followed. An appropriate size limit should be set for the shadow copies. Volumes that have many files changed daily should have larger limits than volumes whose data does not change very often. Also, shadow copies should be scheduled to run more often on heavily used drivesat least twice a day. Shadow copies should be stored on separate volumes if possible. This gives an administrator better performance backing up and restoring data to and from shadow copies. Lastly, the number of stored volume shadow copies should be monitored to keep management simple.

Limitations

The Volume Shadow Copy service should not be considered a tool for backing up and restoring servers to previous states. The Windows Server 2003 Backup utility should be used to back up the system volume and system state. Volume Shadow Copy works well for data volumes, and that is what Volume Shadow Copy backups should be focused toward. For system drives, Volume Shadow Copy may be used to restore some of the files on the system to a previous state, but Windows File Protection does a reasonably good job of protecting operating system files without volume shadow copies.

Shadow Copy Management Using vssadmin.exe

The command-line tool vssadmin.exe can be used to enable shadow copies on a volume. This tool can be used to configure most of the configuration settings, including deleting previous shadow copies. Combining vssadmin.exe with a scheduled task and a batch file, shadow copy management can be somewhat automated. For example, vssadmin.exe commands can be added to a batch script and configured to delete the oldest shadow copy on a volume at 12:00 p.m. every day.

To use vssadmin.exe to delete the oldest shadow copy on a volume, perform the following steps:

1.	Log on to the desired server using an account with Local Administrator access.
2.	Click Start, Run.
3.	Type cmd.exe and click OK to open a command prompt.
4.	Type vssadmin.exe delete shadows /For=C: /Oldest /Quiet and then press Enter to delete the oldest shadow copy for the C volume.
5.	Type exit and press Enter to close the command prompt and log off the server.

To schedule this operation, create a text document using Notepad, type the command in step 4, and then press Enter. Save the file with a .bat or .cmd extension. Finally, open the Control Panel, select Scheduled Tasks, and create a new task to execute this file during the desired schedule.