HP XP RAID Manager Software User Manual

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

2. Host B detects the failure in host A and issues the takeover command

to make the S-VOL usable. If the S-VOL can continue processing,
host B takes over from host A and continues processing.

3. While host B is processing, the P-VOL and S-VOL can be swapped

using full copy (pairsplit –S, paircreate –vl) and the data updated by
host B is fed back to the new S-VOL, host A.

4. When host A recovers from the failure, host A takes over processing

from host B through the horctakeover swap-takeover command.

XP256 microcode 52-47-xx and over

XP512/48 microcode 10-00-xx and over

XP1024/128

XP10000

XP12000

P-VOL recovers.

pairresync

-swaps

Takeover

Host A

Host B

vol

Host A

Host B

vol

unnecessary

Host A goes down.

Host A

Host B

vol

Vol

Host A

Host B

vol

Svol

SSUS

(SSWS)

Host A

Host B

vol

e Only Difference data copied

P-VOL goes down.

Mirroring state

Takeover state

Recovery state

Failover

upon primary

host failure

Failover

upon primary

storage failure