Dell EqualLogic PS6210XS EqualLogic Group Manager Administrator s Guide PS Ser - Page 224

16 About Backing Up and Protecting Your Data A PS Series group is part of a comprehensive backup and data protection solution. Snapshots provide quick recovery and offloading backup operations. On a PS Series group, the system creates the copy instantly and maintains it on disk storage within the group. It does not disrupt access to the volume and requires minimal impact on running applications. Snapshots can provide a stable copy of data for copying to backup media. Restore operations are more reliable because snapshots ensure the integrity of the backed-up data. Cloning a volume creates a duplicate volume with a new name and iSCSI target. You can then create a writable volume. Replication protects data from serious failures such as destruction of a volume during a power outage, or a complete site disaster. Asynchronous replication remotely replicates data from one PS Series group to another over a standard IP network over long distances. You can quickly configure volumes for replication. The PS Series arrays manage the underlying hardware resource complexity. Synchronous replication allows replication across two different storage pools in the same PS Series group, resulting in two hardware independent copies of the volume data. You can create schedules to automatically perform volume and NAS container operations at a specific time or on a regular basis (for example, hourly or daily). The Manual Transfer Utility (MTU) allows you to export a volume on to a transportable media so you can send or carry the media to a remote site. About Volume Data Protection Dell recommends that you use snapshot and replication functionality to protect volume data. A snapshot is a point-in-time representation of a PS Series iSCSI volume. Seen on the network as an iSCSI target, this snapshot is maintained in an array as deltas from the original volume. Snapshots can protect against human error, viruses, or database corruption. You can recover data from a snapshot by setting it online or by restoring the volume from a snapshot. To protect against disasters, you can replicate volume data from one group to another. A replica is a point-in-time representation of a PS Series iSCSI volume. The original volume and its replica are located on different PS Series groups (replication partners) potentially separated by some geographical distance to facilitate disaster tolerance. The replicated volume that is located on a different group does not depend on the original volume so that, in the event of a disaster, you can host the volume from the recovery group and later fail back to the original group with minimal disruption to users. Synchronous replication (SyncRep) is the simultaneous writing of volume data across two different storage pools in the same PS Series group, resulting in two hardware-independent copies of volume data. Each write must go to both pools before the write is acknowledged as complete. If one pool is not available, you can obtain volume data from the other pool. Dell recommends that you protect data by using a robust backup application as a precaution in the event of multiple drive failures, in addition to snapshot and replication functionality. 224 About Backing Up and Protecting Your Data