Checking s-vol currency with the p-vol, Transferring operations back to the primary site – HP XP P9500 Storage User Manual

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4.

At the secondary site, connect to each remote system and release all Continuous Access
Synchronous pairs.

When an S-VOL changes to simplex, you cannot distinguish it from a non-Continuous Access
Synchronous simplex volume. If necessary, use the volume manager to change the volume
labels of the S-VOLs.

5.

Complete file recovery procedures.

6.

When file recovery procedures have been completed, vary the S-VOLs online.

7.

At the secondary site, start critical host operations, with the previous S-VOLs now the primary
volumes.

Checking S-VOL currency with the P-VOL

An S-VOL's currency refers to whether S-VOL data is identical to data in the P-VOL. This is dependent
on your Fence Level setting, which determines whether data is copied to the P-VOL if an error
occurs during an update to the S-VOL.

The following table shows S-VOL currency information, based on pair status and the P-VOL fence
level setting.

Currency of S-VOL

Fence level

Type

S-VOL status

Not current. The S-VOL does not belong to a Continuous Access
Synchronous pair. Even if you have created a Continuous Access

Data Status
Never

--

SMPL

Synchronous pair using this volume, if the pair status is still SMPL, you
must regard its data as not current with the P-VOL.

Not current. The S-VOL is not synchronized because not all tracks have
been copied from the P-VOL yet. This S-VOL must be initialized (or
copied from the P-VOL at a later time).

Data Status
Never

--

COPY

Current. The S-VOL is synchronized with its P-VOL.

Data Status

--

PAIR

* Needs to be analyzed. The S-VOL requires further analysis to
determine its level of currency.

Never

Not current. The S-VOL is not synchronized because not all tracks have
been copied from the P-VOL yet. The S-VOL must be initialized (or
copied from the P-VOL at a later time).

Data Status
Never

Initial copy
failed

PSUE

Suspect. The S-VOL is not synchronized with its P-VOL if any write I/Os
were issued to the P-VOL after the pair was split. The pair should be

Data Status
Never

P-VOL by
operator

PSUS

released and restarted using Entire Volume for Initial Copy option. If
you are sure that no data on the P-VOL changed, you can use the None
option.

Current. The S-VOL is synchronized with its P-VOL.

Data

All other types

PSUS or PSUE

Suspect. The S-VOL is not synchronized with its P-VOL if any write I/Os
were issued to the P-VOL after the pair was split. Restore the consistency

Status Never

of the S-VOL and update it, if required. The time of suspension indicated
on the Last Update Time field of the Detailed Information dialog box
(MCU SVP time) will help to determine the last time the S-VOL was
updated.

For pairs with a P-VOL fence level setting of Never, further analysis is required to determine the S-VOL currency. This can be
determined by using sense information transferred via host failover, or by comparing the contents of the S-VOL with other files
that are confirmed to be current (for example, database log files). The S-VOLs should be recovered using the files that are
confirmed to be current.

Actual data recovery must be done using recovery point data in the database redo log.

Transferring operations back to the primary site

When host operations are running at the secondary site, the primary site should be restored and
operations transferred back.

Transferring operations back to the primary site

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