Configuring Volume Shadow Copy on Windows Server 2008
Windows Server 2008 Volume Shadow Copy is a mechanism whereby the contents of shared folders can be automatically backed up at pre-determined intervals to a shadow volume. Once implemented, shadow copy will backup the previous 64 versions of each file in the shadowed volume and provide users with the ability to restore files from any of the previous 64 versions without administrator intervention, enabling users to independently restore deleted, damaged or overwritten files from the shadow copy. In addition to restoring individual files to a previous version, shadow copy also provides the ability to restore an entire volume from the shadow copy.
Another use for shadow copy is to enable the backup of locked or open files. Ordinarily, if a file is currently open or locked by an application tools such as Windows Backup will fail to backup the file. Shadow copy aware backup tools are, however, able to avoid this problem by using the Volume Shadow Copy Service API.
Shadow Copy Considerations
There are a number of issues that need to be considered when implementing shadow copy for shared folders. First and foremost, the shared folders which are to shadowed need to be identified. Secondly, a location for the shadow to be stored must be allocated. This can reside either on the same volume as the shared folder, or on a completely different volume or disk drive. Even before any data is shadowed, the shadow copy system requires 300MB of available space. The total amount of space required will depend on the size of the shared folder which is to be shadowed and the frequency with which the files are likely to change (since shadow copy will only take new snapshots of files which have changed since the last snapshot). Finally, the time and frequency of the volume snapshots needs to be defined. By default, Shadow Copy performs a snapshot twice a day at 7:00am and 12:00pm.
Once the Shadow Copy system has been configured the shadow copy client needs to be set up on the systems of any users that are likely to need to be able to restore files in the shared folder.
