This is a copy method to execute SnapOPC+ of ETERNUS Disk storage system.
SnapOPC+ uses the Copy-On-Write method to create a pre-update copy source volume.
For details on the operation procedures, refer to "Perform the Advanced Copy" in the "ETERNUS SF Web Console Guide".
SnapOPC+ can save pre-update data on the copy source volume on a per snap generation (unit of volume replication) basis.
SnapOPC+ is designed in view of its mechanism and features to be used as backups for recovery from software failures such as operation mistake and software error.
If a copy source volume becomes inaccessible due to any hardware failure, the relevant session will become an error, thus making it impossible to properly read the data on the copy destination volume.
To provide for such critical hardware failures, it is recommended to make a complete copy of data using clone copy (OPC/QuickOPC/EC) or remote copy (REC) as well as SnapOPC+.
The snapshot copy (SnapOPC+) is effectively available for:
Backups of temporary files used for cascade copy to alternate media such as tape.
Backups of file servers and other data less frequently updated.
Figure 4.6 Snapshot copy (SnapOPC+) diagram
Note
ETERNUS DX80 S2/DX90 S2 need one or more Snap Data Pool Volumes.
