Analyze r-vol currency, Transfer operations back to the main site – HP XP P9500 Storage User Manual

Page 76

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1.

Clear the remote copy SIMs from the RCUs before OS IPL. Connect to each RCU, open
the Continuous Access Synchronous Z System Option window, and click Clear SIM.

2.

Perform an IPL of the remote host system.

3.

Wait until the IPL is complete, and then vary the R-VOLs online (if they did not come online
automatically).

10. At the remote site, start critical host operations, with the previous R-VOLs now the main volumes.

Analyze R-VOL currency

Use the following table to determine an R-VOL’s currency based on pair status and M-VOL fence
level setting.

Table 31 Analyzing R-VOL currency

Currency of R-VOL

Fence level

Type

R-VOL status

Inconsistent. This R-VOL does not belong to a Continuous Access
Synchronous Z pair. Even if you established a Continuous Access

Data Status
Never

--

Simplex

Synchronous Z pair for this volume, you must regard this volume
as inconsistent.

Inconsistent. This R-VOL is not synchronized because not all tracks
have been copied from the M-VOL yet. This R-VOL must be
initialized (or copied from the M-VOL at a later time).

Data Status
Never

--

Pending Duplex

Current. This R-VOL is synchronized with its M-VOL.

Data Status

--

Duplex

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

Never

Inconsistent. This R-VOL is not synchronized because not all tracks
have been copied from the M-VOL yet. This R-VOL must be
initialized (or copied from the M-VOL at a later time).

Data Status
Never

Initial copy
failed

Suspended

Suspect. This R-VOL is not synchronized with its M-VOL if any
write I/Os were issued to the M-VOL after the pair was

Data Status
Never

R-VOL by
operator

Suspended

suspended. This pair should be released and restarted using
Entire Volume for Initial Copy option. If you are sure that no data
on the M-VOL changed, you can use the None option.

Current. This R-VOL is synchronized with its M-VOL.

Data

All other types

Suspended

Suspect. This R-VOL is not synchronized with its M-VOL if any
write I/Os were issued to the M-VOL after the pair was

Status Never

suspended. Restore the consistency of this R-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 this R-VOL was updated.

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

Transfer operations back to the main site

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

In the following procedure, you will establish Continuous Access Synchronous Z pairs at the remote
site, with data flow moving from the remote site to the local. After the pairs are synchronized and
in Duplex status, they will be released, then new pairs will be created at the local site with data
flow moving from local to remote, as originally set up.

76

Planning and procedures for disaster recovery

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