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Delete pair operation, Shadowimage options, Table 6 types of shadowimage options – HP StorageWorks XP Remote Web Console Software User Manual

Page 26: 6 types of shadowimage options

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ShadowImage for the XP128/XP1024/XP10000/XP12000

and quick restore cannot be performed on suspended pairs. While the resync operation for a split pair can

be very fast, the resync operation for a suspended pair will take as long as the initial copy operation.
The XP128/XP1024/XP10000/XP12000 will automatically suspend an SI390 pair when it cannot keep

the pair mirrored for any reason. When the XP128/XP1024/XP10000/XP12000 suspends a pair, sense

information is generated to notify the host. The XP128/XP1024/XP10000/XP12000 will automatically

suspend an SI390 pair under the following conditions:

When the XP128/XP1024/XP10000/XP12000 detects an error condition related to an update copy

operation.

When the S-VOL and/or T-VOL track map in shared memory is lost (for example, due to offline

microprogram exchange). This applies to SP-pend and V-split pairs only. For duplex, split, resync, or

resync-r pairs, the pair is not suspended but the entire S-VOL (T-VOL for reverse resync) is marked as

difference data.

Use the Suspend Volume Pair window (see

Suspending ShadowImage Pairs

” on page 59) to suspend

SI390 pairs. When a pair is suspended, the pair status changes to suspended. When the resync operation

starts, the pair status changes to resync. The S-VOL remains fully accessible while suspended and during

the resync operation. Use the Resynchronize Volume Pair window (see

Resynchronizing ShadowImage

Pairs

” on page 57) to resynchronize suspended SI390 pairs.

NOTE:

The PPRC commands do not support the SI390 suspend operation. You must use the SI390 remote

console software to suspend SI390 pairs. The CSUSPEND and PPRCOPY SUSPEND commands execute an

SI390 split operation instead of a suspend operation. For more information on using PPRC commands to

perform SI390 operations on the XP128/XP1024/XP10000/XP12000, see

Using PPRC Commands for

ShadowImage

” on page 68.

Delete Pair Operation

The SI390 delete pair operation stops the SI390 update copy operations to the T-VOL of the pair and

changes the pair status of both volumes to simplex. An SI390 pair can be deleted by the user at any time

except during the quick split operation (that is, any status except simplex and V-split). After you delete an

SI390 pair, the T-VOL is still not available for write operations until the reserve attribute is reset.
Use the Delete Volume Pair window (see

Deleting ShadowImage Pairs

” on page 60) to delete SI390

pairs. When an SI390 pair is deleted, pending update copy operations for the pair are discarded, and

the status of the S-VOL and T-VOL is changed to simplex.

CAUTION:

The T-VOL of a duplex pair may not be identical to its S-VOL, due to the asynchronous SI390

update copy operations. To synchronize the volumes before deleting the pair, you must split the pair first

(see ”

Deleting ShadowImage Pairs

” on page 60 for instructions).

ShadowImage Options

By using the SI390 options, you can extend the standard SI390 operations such as the add pair and

resync pair operations. The following table shows the options that are currently available.

Table 6

Types of ShadowImage

options

Option Type

Features

Requirement

Swap&Freeze

Swap&Freeze option suppresses the update

copy. For details, see ”

Swap&Freeze Option”

on page 27

.

You must change the subsystem setting to allow

the quick restore operation.

Host I/O

Performance

Host I/O Performance option suppresses the

copy operations by ShadowImage for z/OS.

For details, see ”

Host I/O Performance Option”

on page 27

.