HP XP Continuous Access Software - Manual (Page 101)

Continuous Access XP user guide for the XP1024/XP128 101
Analyzing consistency of Continuous Access XP Asynchronous S-VOLs
Table 21 shows how to determine the consistency of a Continuous Access XP Async S-VOL based on its
pair status and consistency status. For Continuous Access XP Async S-VOLs with a consistency status of LU,
the volume is not consistent with other volumes in the same group, and further analysis is required to
determine the currency of each of these S-VOLs. Determine currency of these S-VOLs using the sense
information transferred via host failover software or comparing contents of the S-VOL with other files
confirmed to be current (such as database log files). These S-VOLs should be recovered using files
confirmed to be current.
Remember that the Continuous Access XP Async time-stamp and C/T information indicates MCU service
processor time, not host system time.
NOTE: Actual data recovery must be done using recovery point data in the database redo log.
PAIR Data
Status
Current. This S-VOL is synchronized with its P-VOL.
Never Needs to be analyzed. This S-VOL requires further analysis to determine its
level of currency.
PSUE -
initial copy failed
Data
Status
Never
Inconsistent. This S-VOL is not synchronized because not all cylinders have
been copied from the P-VOL yet. This S-VOL must be initialized (or copied
from the P-VOL at a later time).
PSUS -
S-VOL by
operator
Data
Status
Never
Suspect. This 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. This pair should be restarted
using the Entire Volume initial copy option, but the None option can be used
if you are sure no data on the P-VOL changed.
PSUS/PSUE -
all other types
Data Current. This S-VOL is synchronized with its P-VOL.
Status
Never
Suspect. This 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 or suspended. Restore consistency
of this S-VOL and update it, if required. The time of suspension indicated on
the Pairdisplay pane helps determine the last time this S-VOL was updated.
Table 20 Determining Continuous Access XP Synchronous S-VOL currency based on its pair status and
P-VOL fence-level setting (continued)
Status of S-VOL Fence level Currency of S-VOL
Table 21 Determining Continuous Access XP Async S-VOL consistency based on its pair status and
consistency status
Status of
S-VOL
Usable for
Recovery?
Description
PAIR
COPY
SMPL No These states do not usually occur during Continuous Access XP Asynchronous
disaster recovery because the RCU suspends all Continuous Access XP Async
S-VOLs when communications with the MCU is lost. Continuous Access XP
Async S-VOLs in these states should not be used for disaster recovery.
Simplex volumes cannot be distinguished from S-VOLs already deleted by the
pairsplit-S operation.