HP XP Continuous Access Software - Manual (Page 349)

HA Failover and failback 349
XP256 microcode 52-47-xx and over
XP512/48 microcode 10-00-xx and over
XP1024/128
XP10000
XP12000
The swap-takeover function no longer uses “Simplex” and “No Copy”
mode for swapping. This assures greater mirror consistency. Moreover, it is
included as a function of SVOL-takeover.
1. The command orders a “suspend for swapping” (SSWS) for the local
volume (S-VOL).
If this step fails, the swap-takeover function is disabled and returns an
error.
2. The command orders a “resync for swapping” to switch to the primary
volume. The local volume (S-VOL) is swapped as the NEW_PVOL.
The NEW_SVOL is resynchronized based on the NEW_PVOL.
If the remote host is known, the command will use the value of P-VOL
specified at paircreate time for the number of simultaneous copy
tracks. If the remote host is unknown, the command will use a default
of 3 simultaneous copy tracks for “resync for swapping.”
If this step fails, the swap-takeover function is returned at
SVOL-SSUS-takeover. The local volume (S-VOL) is maintained in
the SSUS (PSUS) state which permits WRITE and maintenance of
delta data (BITMAP) for the secondary volume. This special state is
also displayed as the SSWS state, using the –fc option of the
pairdisplay
command.
Async-CA Extended Specific Behavior
XP256 microcode 52-47-xx and under
XP512/48 microcode 10-00-xx and under
1. The P-VOL side RM issues a pairsplit command to the P-VOL side
disk array.
2. Non-transmitted data that remains in the FIFO queue (sidefile) of the
P-VOL is copied to the S-VOL side.