Resynchronizing pairs – HP XP P9500 Storage User Manual
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5.
From the Suspend Kind drop-down menu, specify whether or not to continue host I/O writes
to the P-VOL while the pair is split. (This field is disabled if run from the S-VOL.)
•
Select P-VOL Failure not to allow write I/O to the P-VOL while the pair is split, regardless
of the P-VOL fence level setting. Choose this setting if you need to maintain synchronization
of the ESAM pair.
•
Select S-VOL to allow write I/O to the P-VOL while the pair is split. The P-VOL will accept
all subsequent write I/O operations after the split. The primary system will keep track of
updates while the pair is split. Choose this setting if the P-VOL is required for system
operation and you need to keep the P-VOL online while the pair is split.
6.
Click Set. The settings display in the Preview area.
7.
In the Preview list, check the settings. To change a setting, right-click and select Modify. When
satisfied, click Apply. The primary system will complete all write operations in progress before
splitting the pair, so that the pair is synchronized at the time of the split.
8.
Verify that the operation is completed successfully by checking the Status column. Status should
be PSUS.
Resynchronizing pairs
When you resynchronize a split pair, the volume that was not being updated—usually the S-VOL—is
synchronized with the volume that was being updated by the host—usually the P-VOL.
Prerequisite information:
•
The method for performing this operation differs according to whether the P-VOL or the S-VOL
is accepting write I/O from the host. Determine which volume is online by checking the VOL
Access column in the Pair Operation window.
◦
Pairs must be in PSUS or PSUE when the P-VOL is receiving I/O. If status is PSUE, clear
the error before resynchronizing. The operation can be performed using the Remote Web
Console procedure below.
◦
When the S-VOL is receiving host I/O, pair status must be SSWS. The operation is
performed using the RAID Manager pairresync -swaps command. See
for more information.
•
Pair status during resynchronization changes to COPY.
•
Status changes to PAIR when the operation is complete.
•
If you want to resynchronize the pair that has been released from the S-VOL side, do not use
this procedure. Instead, release the pair from the P-VOL side using the Pairsplit-S command;
and then create the pair from the P-VOL side using the Paircreate (ESAM) operation, making
sure to set the appropriate initial copy option (Entire Volume or None).
Procedure 11 To resynchronize pairs:
1.
Access the MCU in Remote Web Console, then click Actions > Remote Copy > Continuous
Access Synchronous > Pair Operation.
2.
Make sure that you are in the modify mode.
3.
In the Pair Operation window tree, select the CU group, CU, port, or host group where the
P-VOL is located.
4.
In the volume list, right-click the P-VOL in the pair to be resynchronized and click Pairresync.
The Pairresync dialog box displays.
5.
The P-VOL Fence Level is automatically set to Never. The volume receiving updates from the
host will never be fenced, or blocked, from receiving host read/write.
6.
From the Copy Pace drop-down menu, select the desired number of tracks to be copied at one
time (1-15) during the copy operation. The default setting is 15. If you specify a large number,
such as 15, copying is faster, but I/O performance of the storage system may decrease. If
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Pair operations