Hitachi TAGMASTORE MK-90RD011-25 - Manual (Page 50)

32 Chapter 2 Overview of CCI Operations
Primary
PAIR
Secondary
PAIR
R/W
Secondary
COPY
Primary
COPY
W (Database flushing)
e
Pair splitting (Read)
d
Event waiting (PAIR)
d
Event waiting (PSUS)
c
Backup request c
Database freezing
OLTP (DB) server Backup server
f
Database unfreezing
Secondary
COPY
Primary
COPY
R/W
Secondary
COPY
Secondary
PSUS
Primary
COPY
g
Pair re-synchronization
Primary
PSUS
Read R/W
f
Backup executing
h
Backup completion
R/W
e
Database mount -r
g
Database unmount
differential data
After copied, the status
changes to"PSUS"
Figure 2.14 Backing Up S-VOL in Paired Status Using ShadowImage
Note: When you issue the pairsplit command to a ShadowImage paired volume, the pair
status changes to COPY, and the differential data due to asynchronous copy is copied to the
secondary volume. When this copy is finished, the pair status changes to PSUS. The primary
volume remains write-enabled throughout the pairsplit operation (COPY and PSUS status).