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1 recovery in case of svol-takeover – Hitachi TAGMASTORE MK-90RD011-25 User Manual

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Chapter 4 Performing CCI Operations

4.7.1 Recovery in Case of SVOL-Takeover

While the DC1 is conducting processing (normally state = 4), and when the DC2 has
recovered from the failure, the following commands must be issued to make PVOL on the
DC1 side:

In case of operations on the DC1 side:
c

pairsplit -S

d

paircreate -vl

e

pairevtwait (wait for PAIR)

In case of operations on the DC2 side:
c

pairsplit -S

d

paircreate -vr

e

pairevtwait (wait for PAIR)

Host A

PVOL
PSUS

DC2

Host B

SMPL

DC1

State No. 4

Host A

SMPL

DC2

Host B

SMPL

DC1

State No. 1

cpairsplit -S

Host A

SVOL

COPY

DC2

Host B

PVOL

COPY

DC1

State No. 15

d

paircreate -vl

Host A

SVOL

PAIR

DC2

Host B

PVOL

PAIR

DC1

State No. 16

epairevtwait

Host A

PVOL

PAIR

DC2

Host B

SVOL

PAIR

DC1

State No. 16

horctakeover

After operations (state is No.16), when the DC2 takes over processing from the DC1, the
horctakeover command will execute a swap-takeover operation due to (DC2)SVOL &
(DC1)PVOL_PAIR on the (DC2) side.

If the DC1 side has NO this operation, and when the DC2
takes over processing from the DC1, horctakeover command
will be returned with EX_VOLCRE due to (DC2)PVOL &
(DC1)SMPL on the (DC2) side.
Æ

state is No. 10.

In this case, pairvolchk (-s) command will be returned with
PVOL_PSUS on the (DC2) side, and pairvolchk (-s -c)
command will be returned with SMPL on the (DC2) side.

Host A

PVOL
PSUS

DC2

Host B

SMPL

DC1

State No. 10