Universal Replicator; Shadowimage; Configurations With Shadowimage P-Vols - Hitachi G200 User Manual

• Monitor system performance during TC operations and during testing
activities.
See the Performance Guide for Hitachi Virtual Storage Platform Gx00 and
Fx00 Models for more information.

Universal Replicator

As with TrueCopy, Universal Replicator provides remote data replication for
backup and disaster recovery purposes. TrueCopy copies data synchronously
between the primary and secondary sites to keep the data at both sites
identical, whereas Universal Replicator copies data asynchronously, and the
data in the secondary site is updated later than the data in the primary site.
The TrueCopy primary and secondary sites must be closer to each other than
the primary and secondary sites for Universal Replicator, as TrueCopy
operations can be affected by the distance between the sites.
By combining Universal Replicator and TrueCopy, you can take advantage of
the benefits of each product to achieve better failure and disaster recovery
solutions.
For details about configurations that combine Universal Replicator and
TrueCopy, see the Hitachi Universal Replicator User Guide.

ShadowImage

ShadowImage volumes can be assigned to TC pairs, and TC volumes can be
assigned to SI pairs. The following table shows the configurations that are
possible.
P-VOL
S-VOL
Please note the following when sharing TC volumes with SI volumes.
• L1 and L2 SI pairs can be shared with TC volumes. Both node and leaf S-
VOLs are considered secondary volumes by TC.
• SI is recommended for in-system copy operations. However, if SI is not
installed, TC can be used to copy within the same storage system. This
configuration requires at least one fibre cable loop.
• The SI Quick Restore can be performed when the TC pair is suspended.
For information about the Quick Restore operation, see the Hitachi
ShadowImage® User Guide.

Configurations with ShadowImage P-VOLs

TC can share a SI P-VOL in three configurations:
Hitachi TrueCopy® User Guide for Hitachi Virtual Storage Platform Gx00 and Fx00 Models
TC volume
Yes
Yes
Sharing TrueCopy volumes
SI P-VOL
Yes
No
SI S-VOL
4-7