Administrator Guide

NOTE: Resetting the Windows IO structure is necessary only if you also want to make the new
volume a cluster resource. You can recover the volume on a node of a cluster without resetting
the IO structure and still use it as a non-clustered disk. However, some clustered applications
(like SQL Server) cannot use a volume if it is not a clustered disk.
Related links
Using Replay Manager as Part of a Disaster Recovery Plan
Local Volumes
Replay Manager provides the ability to create VSS backups of one or more local volumes mapped from
the server to the Dell Storage Center.
NOTE: In the case of a Windows 2008 R2 Local Volume cluster, if the user has an RMS schedule set
to execute on a CSV volume, the schedule executes on all nodes of the cluster that have an RMS
service running on them. Only one node of the cluster will be successful in the backup.
VSS for Local Volumes
Using the Local Volumes option, an administrator can use VSS to create backups of applications without
using a Replay Manager application-specific extension; however, it is up to the administrator to
determine which volumes are needed for a complete backup set.
For example, the complete backup set for an Exchange Server with separate database volumes and log
volumes for a storage group requires the manual selection of all volumes and logs for the storage group.
Therefore, the administrator must know the exact layout and location of all storage group components to
create a usable backup set.
The Local Volumes option is primarily intended for backing up and restoring volume file and print
environments where the files are flat—that is, the files are not in a transactional database-like
environment. Servers that contain shared files or home directories can leverage the Local Volumes
backups because the restore points for local volumes can be easily exposed, allowing an administrator to
recover files.
VSS for Shared Folders
VSS for Shared Folders, a similar technology built into Windows, provides the ability to back up a volume
which in turn stores the shadow copy on the volume itself in a hidden location. By default, snapshots in
VSS for Shared Folders take place at 7:00 a.m. and 12:00 p.m., and shadow copies are replaced as
required by the amount of free disk space on the volume. The snapshot times can be adjusted, but the
snapshots should run no more than once every 60 minutes.
An advantage that VSS for Shared Folders provides is the ability for Windows XP and Windows Vista clients
to recover files from a shadow copy without administrator intervention. By combining Replay Manager
and some custom scripting using the Dell Storage Center Command Set for PowerShell, a solution that
provides the same functionality could be developed.
Using VSS for Shared Folders and Replay Manager on the same volumes is not recommended as this
combination uses additional disk space because VSS stores the deltas (data changes or differences)
hidden on the volume while Storage Center determines which blocks to freeze. This is essentially
duplicating efforts on the volume.
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