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HP XP P9000 Continuous Access Synchronous for Mainframe Systems User Guide

ManualsBrandsHP ManualsStorageHP XP P9500 Disk Array
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• SSIDs: The MCUs to which the CGROUP command will be issued must have consecutive SSIDs.
The HP representative configures the SSIDs on the XP P9500 SVP.
CAUTION: MVS requires that the storage system be offline during SSID changes.
Reconfiguring SSIDs is therefore a disruptive event that must be carefully planned.
Also, SCP time specified from Remote Web Console's CU Option dialog box is invalid for
pairs created using a consistency group from Business Continuity Manager. You can, however,
specify SCP time for these pairs using the YKFREEZE command (range from 1 to 5 seconds).
If a failure suspension occurs, then SCP time becomes fixed at 120 seconds and cannot be
changed.
• When you run CGROUP FREEZE or RUN, the following information must be specified:
The device, which is the Cnt Ac-S Z P-VOL or simplex volume LDEV ID (DEVN parameter)◦
◦ The MCU, which consists of the serial number and lowest SSID in the CU (PRIM parameter).
◦ The RCU, which consists of the serial number and lowest SSID in the CU (SEC parameter).
Pair status before and after CGROUP FREEZE/RUN
The following table shows pair status for P-VOLs and S-VOLs before and after CGROUP FREEZE/RUN
operations.
After CGROUP/RUNAfter CGROUP/FREEZEBefore CGROUP FREEZE/RUN
S-VOLP-VOLS-VOLP-VOLS-VOLP-VOL
—Simplex—Simplex—SimplexStatus
PendingSuspendedPendingSuspendedPendingPending
DuplexSuspendedDuplexSuspendedDuplexDuplex
SuspendedSuspendedSuspendedSuspendedSuspendedSuspended
Using CGROUP
The following figure shows a simple example of the CGROUP FREEZE/RUN command implemented
in a GDPS environment.
Figure key:
1. Read/write I/Os are issued from the host.
2. A failure occurs on an P-VOL, and the MCU suspends the pair.
3. Suspend and extended long busy state are reported to the host.
4. The 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.
I/O control after failure—with CGROUP FREEZE/RUN 117