Hitachi G200 User Manual page 70

• In the following figure, the TC P-VOL also functions as a SI P-VOL. This
configuration allows you to use SI for on-site data backup in case of TC
failure. Or, the TC S-VOL can be used to provide remote backup of the SI
P-VOL in case of a SI failure.
In this configuration, you can only delete TC pairs when the SI P-VOL
status is RCPY. The following table shows possibilities of TC pair
operations according to the SI P-VOL status.
SI P-VOL
COPY(PD)/
COPY
COPY(SP)/
COPY
COPY(RS)/
COPY
PAIR
PSUS(SP)/
PSUS
PSUS
PSUE
COPY(RS-
R)/RCPY
• In the following figure, the TC S-VOL also functions as a SI P-VOL. In this
configuration, SI provides another (or several more) backup copies of a
TC P-VOL.
When a SI P-VOL is shared with the TC S-VOL, the write operation to the
TC P-VOL takes a longer time than normal. This is especially true when
the SI pair is in the PSUS(SP)/PSUS status and is caused by the SI
copying process.
4-8
Hitachi TrueCopy® User Guide for Hitachi Virtual Storage Platform Gx00 and Fx00 Models
Figure 4-1 Shared TC P-VOL with SI P-VOL
status
Create
Yes Yes
Yes Yes
Yes Yes
Yes Yes
No No
Sharing TrueCopy volumes
TC pair operations
Split Resync Delete
Yes Yes
Yes Yes
Yes Yes
Yes Yes
No Yes
Switch operations
between the primary
and secondary sites
(horctakeover)
Yes
Yes
Yes
Yes
No