Transferring operations back to the main site, Analyzing the, Consistency of truecopy asynchronous r-vols – HP StorageWorks XP Remote Web Console Software User Manual
Page 149
Hitachi TrueCopy for z/OS user guide 149
Analyzing the consistency of TrueCopy Asynchronous R-VOLs
The following table shows how to determine the consistency of a TC390A R-VOL based on its pair status
and consistency status. For TC390A R-VOLs with a consistency status of Volume, the volume is not
consistent with other volumes in the same group and further analysis will be required to determine the
currency of each of these R-VOLs. To determine the currency of these R-VOLs, use the sense information
transferred through ERC or compare the contents of the R-VOL with other files that are confirmed to be
current, such as DB2 log files. These R-VOLs should be recovered using the files that are confirmed to be
current.
Transferring operations back to the main site
After the applications are running at the remote site, the next activity is to restore the main site and transfer
operations back to the main site.
NOTE:
For Fibre Channel interface, do not use the CESTPATH and CDELPATH commands at the same
time as the SCSI path definition function of LUN Management. The Fibre Channel interface ports need to
be configured as initiator ports or RCU target ports before the CESTPATH and CDELPATH commands are
issued.
Suspended -
all other types
Data
Current. This R-VOL is synchronized with its M-VOL.
Status
Never
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 suspended. Restore the
consistency of this R-VOL and update it, if required. The system time stamp
information transferred through ERC or the time of suspension indicated on
the Pair Status window will help to determine the last time this R-VOL was
updated.
Table 26
Analyzing the currency of TrueCopy Synchronous R-VOLs (continued)
Status of R-VOL
Fence
Level
Currency of R-VOL
Table 27
Analyzing the consistency of TrueCopy Asynchronous R-VOLs
Status of R-VOL
Usable for
Recovery?
Description
Duplex
Pending Duplex
Simplex
No
No
No
These states do not usually occur during TC390A disaster recovery
because the RCU suspends all TC390A pairs when communication with
the MCU is lost. TC390A R-VOLs in these states should not be used for
disaster recovery.
Simplex volumes cannot be distinguished from R-VOLs that have already
been deleted by the Delete Pair operation.
Suspended-Group
Yes
The update sequence consistency across these R-VOLs is ensured at the
point in time indicated by the group consistency time. These R-VOLs can
be used for disaster recovery at the secondary system.
Updates that were performed at the primary system after the indicated
consistency time were probably lost.
Suspended-Volume
No
The contents of this R-VOL may be behind the other R-VOLs in the
consistency group. If this volume must be consistent with the other volumes
in the same group, this R-VOL should not be used for disaster recovery.
The cause for this status is:
The TC390A Error Level pair option for this pair is Volume (not Group).
Also, this pair was suspended before the disaster/failure, at the
beginning of the rolling disaster, or during the initial copy operation.