• Recover files that were accidentally deleted. Previous versions can be opened and copied to
asafelocation.
• Recover from accidentally overwriting a file. A previous version of that file can be acc essed.
• Compare several versions of a file while working. Use previous versions to compare changes
between two versions of a file.
Shadow copies c annot replace the current backup, archive, or business recovery system, but they can
help to simplif y restore procedures. Because a snapshot only contains a portion of the original data
blocks, shadow copies can not protect against data loss due to med ia failures. However, the strength
of snapshots is the ability to instantly recover data from shad ow copies, reducing the number of times
needed to restore data from tape.
Shadow copy planning
Before setup is initiated on the server and the client interface is mad e available to end users, consider the
following:
• From what v
olume will shadow copies be taken?
• How much disk space should be allocated for shadow c opies?
• Will separate d isks be used to store shadow copies?
• How freque
ntly will shadow copies be made?
Identifying the volume
Shadow copies are taken for a complete volume, but not for a specificdirectory. Shadowcopies
work best when the server stores user files, such as documents, spreadsheets, presentations, graphics,
or database files.
NOTE:
Shadow copies should not be used to provide acc ess to previous versions of application or e-ma il
databases.
Shadow copies are designed for volumes that store user data such as home d irectories and My Documents
folders that are redirected by using Group P olicy or other shared folders in which users store data.
Shadow copies work with compressed or encrypted files and retain whatever permissions were set on the
files when the shadow copies were taken. For example, if a user is denied permission to read a file,
that user would not be able to restore a previous version of the file, or be able to read the file a f ter
it has been r estored.
Although shadow copies are taken for an entire volume, users must use shared folders to access sha dow
copies. Administrators on the local server must also specify the \\servername\sharename path to
access shadow copies. If administrators or end users want to access a pre vious version of a file that does
not reside in a shared folder, the administrator must firstsharethefolder.
NOTE:
Shadow copies a re available only on NTFS, not FAT or FAT32 volumes.
Files or folders that are recorded by using Shadow Copy appear static, even though the original data is
changing.
Allocating disk space
When determining the amo unt of space to allocate for storing shadow copies, consider both the number
and size of fi les that are being copied, as well as the frequency of changes between copies. For
example, 100 files that only change monthly require less storage space tha n 1 0 files that change daily. If
HPProLiantDL380G5StorageServer 63
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