To suspend one or more tc390 volume pairs – HP StorageWorks XP Remote Web Console Software User Manual
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TrueCopy for z/OS user guide 121
• R-VOL. The M-VOL will accept all subsequent write I/O operations and the MCU will keep track of
updates while the pair is suspended. Use this setting if you need to keep the M-VOL online. This
setting is functionally equivalent to CSUSPEND without the optional PRIMARY parameter.
•
Asynchronous Parameters:
• Suspend Range: Use this option to select the TC390A suspend group operation. The CSUSPEND
TSO command supports the TC390A suspend group operation (see ”
Group. The MCU/RCU will suspend all other TC390A pairs in the same consistency group as the
specified pair(s).
Volume. The MCU/RCU will suspend only the specified TC390A pair(s) (even if the error level of the
pair is group).
NOTE:
With the setting of Volume for Suspend Range, if there are Duplex status pairs and pairs
other than Duplex status in the same consistency group, unexpected suspend may occur during the
pair operations (Suspend, Delete, and Resume) under the heavy I/O load conditions. You can
estimate whether the I/O load condition is heavy or not from the rate of sidefile cache (around
30%), or from the frequency of the host I/O if you cannot see the rate of sidefile cache. The pair
operations should be performed under the light I/O load condition.
• Pending Update: This option specifies the TC390A suspend mode. The CSUSPEND TSO command
supports the TC390A suspend mode option (”
Using PPRC Commands for TrueCopy
Drain. The RCU will finish settling all pending recordsets for the pair as soon as the RCU accepts
the suspend operation. After settling all the recordsets, if there is no recordset for a fixed period of
time, the MCU will change the TC390A pair status from suspending to suspended.
NOTE:
If the RCU is not able to complete these actions within the copy pending timeout setting,
the RCU will discontinue the original suspend request and forcibly suspend the affected volume
pairs. Thus, you can use the copy pending timeout parameter to limit the amount of time it takes to
complete the suspend/drain operation.
Purge. The MCU will change the TC390A pair status from suspending to suspended as soon as the
RCU accepts the suspend operation. The MCU and RCU discard any pending recordsets and mark
the cylinders that contain discarded recordsets as modified in the M-VOL and R-VOL bitmap,
respectively. When the pair is resumed, the M-VOL and R-VOL bitmaps will be merged at the MCU,
and all cylinders marked as modified will be copied to the R-VOL.
NOTE:
If the MCU does not receive acknowledgement of the suspend operation from the RCU
within the copy pending timeout setting, the MCU will forcibly suspend all affected pairs and report
an IEA491E host console message.
To suspend one or more TC390 volume pairs:
1.
Connect to the MCU (or RCU) of the volume pair(s) to be suspended. You do not need to vary the
M-VOL(s) offline. If you want to use the R-VOL write enable option, you must connect to the MCU and
select the M-VOL of the pair.
2.
From the CU Number tree on the TrueCopy main window, select the number of the correct CU image.
3.
From the Volume list on the TrueCopy main window, select the TC390 volume pair(s) that you want to
suspend. Select either TC390 Synchronous or TC390A pairs, but not both. The pair status must be
Duplex.
4.
Right-click to display the pop-up menu and click Suspend Pair. The Suspend Pair window is displayed.
5.
From the Suspend Pair window, select the options for the pair(s), and then click Set to close the Suspend
Pair window and set the parameters. The list changes to the Pair Settings Parameter list (Suspend Pair).
You can modify the options as needed (see ”
Modifying Parameters and Omitting Selected Volumes
page 111). Verify that the Suspend Pair options for each pair are correct. The suspend kind option