Shadow copy is a new feature of Windows Server 2003 that basically takes a snapshot of a file or folder at a given point in time, and stores that snapshot for a configured amount of time. While the value may not be evident at first, it should definitely gain attention when coupled with the age-old problem of tape backups with open files.
Tape backup programs routinely have problems because they cannot accurately or correctly backup data that is currently being used by a program. Many of these backup programs sell add-on programs for certain applications (such as Exchange for email or SQL for databases) in order to ensure proper backup of application-specific files, but these add-ons are expensive, and they don’t always work. As a result, the data is either incorrectly backed up, or not backed up at all.
Shadow copy basically performs a backup of an entire volume, including files that are open, and it also ensures that all file changes that occur between the time the backup began and the time it finished, are also updated on the backup as well. NTBACKUP will not back up shadow copies by default, however other backup programs can be configured to do so, thus avoiding the additional costs of add-on utilities.
Shadow copy is particularly valuable in avoiding the tape restore for small issues where a user has deleted a network-shared file, or when they require an older (hours older) version of the same file. Shadow copy by default will make a shadow copy of a share or volume twice each day.
If or when a file in the shadow copy is deleted, a user can restore that file by right-clicking on the folder where the file existed, and selecting Properties. A new Previous Versions tab will be available if (a) the volume or share is enabled for shadow copy and (b) the client is running the appropriate client software. This software is located in the C:\WINDOWS\system32\clients\twclient\x86 directory, and can be installed en-masse using Group Policies, or on a single Administrative computer which can better monitor file restores.
Shadow copy is enabled within Computer Management in the Shares Section. All you need to do is right-click on the Shared Folders in the left pane, select All Tasks, and select Configure Shadow Copies. From there, you select the volume, click on the Enable button, and the system will proceed with the first shadow copy of the volume.
[tags]microsoft,diana huggins,shadow copy,volume backup,ntbackup[/tags]