Checking S-VOL consistency with the P-VOL

TrueCopy® User Guide

Version
9.8.7
Audience
anonymous
Part Number
MK-98RD9022-18

An S-VOL's consistency 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 consistency information, based on Device Manager - Storage Navigator pair status and the P-VOL fence level setting.

S-VOL status

Split type

Fence level

Consistency of S-VOL

Device Manager - Storage Navigator

CCI

BCM

HDvM - SN

CCI

Unpaired volume

SMPL

SIMPLEX

--

Data, Status, Never

data, status, never

Not consistent. The S-VOL does not belong to a pair. Even if you have created a pair using this volume, if the pair status is still SMPL, you must regard its data as not consistent with the P-VOL.

COPY

COPY

PENDING

--

Data, Status, Never

data, status, never

Not consistent. 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).

PAIR

PAIR

DUPLEX

--

Data, Status

data, status

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

Never

never

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

PSUE

PSUE

SUSPER(50)

Initial copy failed

Data, Status, Never

data, status, never

Not consistent. 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).

PSUS

PSUS

SUSPOP(04)

S-VOL by operator

Data, Status, Never

data, status, never

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

PSUS or PSUE

PSUE

SUSPOP/SUSPER(all other types)

All other types

Data

data

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

Status, Never

status, never

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 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.

Legend:

Data: Data in the secondary volume

Status: Status of the secondary volume

For pairs whose P-VOL fence level in HDvM - SN is Never, or for pairs whose output results of the pairdisplay command for Fence in CCI is never, further analysis is required to determine the S-VOL consistency. This can be determined by using sense information transferred by host failover, or by comparing the contents of the S-VOL with other files that are confirmed to be consistent (for example, database log files). The S-VOLs should be recovered using the files that are confirmed to be consistent.

Note: Actual data recovery must be done using recovery point data in the database operation log.