Using pprc tso commands with cgroup support – HP XP P9500 Storage User Manual

Page 91

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Figure 12 Overview of GDPS operations

Figure key:
1.

Read/write I/Os are issued from the host.

2.

A failure occurs on a Continuous Access Synchronous Z M-VOL, and the MCU suspends the
pair.

3.

Suspend and extended long busy state are reported to the host.

4.

Host reports IEA494I with extended long busy state.

5.

CGROUP/FREEZE commands are issued to groups.

6.

SCP sense bytes are reported if an I/O is issued to a frozen volume.

7.

I/Os are queued at the host.

8.

Switch to remote (secondary) site.

Using PPRC TSO commands with CGROUP support

CESTPATH

: You can use the CESTPATH command to recover a blocked MCU RCU path. Make

sure to use the same parameters as when the path was established.

CESTPAIR

: After you reestablish the MCU RCU path that was blocked, you can use the

CESTPAIR/RESYNC command to resynchronize the Continuous Access Synchronous Z pairs
suspended by the CGROUP/RUN command.

CDELPAIR

: After you reestablish the MCU RCU path that was blocked, you can use the CDELPAIR

command to release the Continuous Access Synchronous Z pairs suspended by the
CGROUP/FREEZE command. If CDELPAIR is issued to a Continuous Access Synchronous Z pair
whose MCU RCU path is still blocked, the MCU rejects the command (F/M=0F, Continuous Access
Synchronous Z error code=5A).

CRECOVER

: You can use the CRECOVER command to change a suspended R-VOL to simplex. This

command is issued to the R-VOL and does not affect the suspended M-VOL.

CQUERY/PATHS

:

Figure 13 (page 92)

show the output of the CQUERY command issued to a

Continuous Access Synchronous Z MCU to which the CGROUP/FREEZE command has been issued.

Figure 14 (page 92)

shows the output of the CQUERY command issued to the Continuous Access

Synchronous Z RCU that has a blocked path due to the CGROUP/FREEZE command.

CGROUP (FREEZE/RUN) support

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