Hitachi TAGMASTORE MK-90RD011-25 - Manual (Page 224)

206 Chapter 4 Performing CCI Operations
Even though ESCON or FC has been connected to S-VOL, PVOL-PSUE-takeover is changed to
the suspend state with the primary volume only (SVOL’s state is not changed), since that
maintains consistence of the secondary volume at having accepted horctakeover command.
Host C Host A Host B
PSUS
PSUE*
PSUS
PSUS
PSUS
PAIR
PSUE
PAIR
PAIR
PAIR horctakeover
P-VOL
SVOL failure
Host C Host A Host B
PAIR
PSUE
PAIR
PAIR
PAIR
PAIR
PSUE
PAIR
PAIR
PAIR
S-VOL P-VOL S-VOL
Group STATUS of the P-VOL. The PSUE and/or PSUS status is intermingled in the group
through action of this PVOL-PSUE-takeover. This intermingled pair status is PSUE as the
group status, therefore the pairvolchk command returned give priority PSUE(PDUB) instead
of PSUS as the group status. Therefore, the group status of the PVOL is also continued after
the PVOL-PSUE-takeover.
4.7.3 Recovery in Case of PVOL-PSUE-Takeover
This special state (PSUE*) turns back to original state after the successful execution of the
pairresync command (after the recovery of ESCON/fibre-channel link). If the pairresync
command has been failed at the ESCON or fibre-channel link is not restored, then this
special state (PSUE*) is NOT changed.
Turns back to
original state
P-VOL
Host C Host A Host B
PSUS
PSUE*
PSUS
PSUE*
PSUS
PAIR
PAIR
PAIR
PAIR
PAIR
S-VOL
Host C Host A Host B
COPY
COPY
COPY
COPY
COPY COPY
COPY
COPY
COPY
COPY
pairresync -l
on Host C
P-VOL S-VOL
Host C Host A Host B
PAIR
PAIR
PAIR
PAIR
PAIR PAIR
PAIR
PAIR
PAIR
PAIR
P-VOL S-VOL