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HP XP Continuous Access Software User Manual

Page 342

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342

HP StorageWorks Disk Array XP RAID Manager: User’s Guide

SVOL-takeover in the case of a host failure

After SVOL-takeover changes the S-VOL (only) to suspend (PAIR,
PSUE

SSUS) state, the SVOL-takeover will automatically execute the

pairresync –swaps

command to copy data between the new P-VOL and

the new S-VOL. The horctakeover command returns a swap-takeover.

Async-CA specific behavior

Before the S-VOL is changed to SSUS, the SVOL-takeover operation will
copy non-transmitted data (which remains in the P-VOL sidefile) to the
S-VOL. The SVOL-takeover operation waits to attempt to copy all P-VOL
data to the S-VOL before a timeout (specified by the –t timeout option).

After all the P-VOL sidefile data has been successfully copied to the
S-VOL, the SVOL-takeover operation splits the pairs and changes the
S-VOL to SSUS state. The remainder of the operation is the same as for the
non-asynchronous case.

horctakeover

P-VOL

Host C

Host A

Host B

PAIR
PAIR
PAIR
PAIR
PAIR

PAIR
PAIR
PAIR
PAIR
PAIR

S-VOL

Host C

Host A

Host B

PSUS
PSUS
PSUS
PSUS
PSUS

SSUS
SSUS
SSUS
SSUS
SSUS

P-VOL

S-VOL

Host C

Host A

Host B

PAIR
PAIR
PAIR
PAIR
PAIR

PAIR
PAIR
PAIR
PAIR
PAIR

S-VOL

P-VOL

Before running APP

internally executes

"pairresync -swap

s

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