When a physical file is backed up with the Snapshot Client, the backup consists of the entire extent. This backup contrasts with stream-based SQL Server backups where only the actual data content of the objects are archived. If you intend to use snapshot technology to back up SQL Server, you may want to use the SQL Server dynamic file allocation. This configuration reduces the likelihood that any of the component files contain large areas of empty space.

Another consideration for choosing between file- and stream-based backups concerns how SQL Server zeroes the target disk area before a stream-based restore. In some cases, the time almost equals the total disk-copy time for restore. For Snapshot Client restores, however, disk zeroing is not done so the total recovery time can be substantially less.

Review the other considerations for SQL Server disk initialization.