Recovery From Svol-Ssus-Takeover - Hitachi TAGMASTORE MK-90RD011-25 User Manual

4.7.5

Recovery from SVOL-SSUS-Takeover

After recovery of the ESCON/FC link, this special state (PVOL_PSUE and SVOL_PSUS) will be
changed to COPY state that original SVOL is swapped as the NEW_PVOL and resynchronizes
(cast off original PVOL) the NEW_SVOL based on the NEW_PVOL by issuing of the
pairresync -swaps command on takeover site (Host B).
Host A
Host C
PAIR
PSUE
PAIR
PAIR
PAIR
P-VOL
If the pairresync -swaps command has been failed at the ESCON/FC link is not restored, then
this special state (PVOL_PSUE and SVOL_PSUS) is NOT changed.
Failback after recovery on Host B. After recovery with execution of the pairresync -swaps
command on Host B, if you stop the applications on Host B and restart the applications on
Host A, then horctakeover will execute Swap-Takeover, even though Host A cannot
communicate with remote Host B.
Host C
horctakeover
on HostA
208 Chapter 4 Performing CCI Operations
Host B
Host C
SSUS
pairresync -swaps
SSUS
on Host B only
SSUS
SSUS
SSUS
S-VOL
Host A
Host B
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
S-VOL P-VOL
Host A
Host B
COPY COPY
COPY COPY
COPY COPY
COPY COPY
COPY COPY
S-VOL P-VOL
Host C Host A
Host B
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
PAIR
P-VOL S-VOL
Host A
Host C
PAIR
Delta COPY
PAIR
PAIR
PAIR
PAIR
PAIR
S-VOL
Host B
PAIR
PAIR
PAIR
PAIR
PAIR
P-VOL