HP XP7 Storage - Manual (Page 56)

Status reporting and data currency
The following table shows the pair status that is reported for different combinations of shared
volumes.
Pair status Number of BC Z S-VOLs Number of Cnt
Ac-S Z pairs
Simplex 0 0
BC Z pair status 1 0
BC Z pair status for the S-VOL with lowest LDEV ID 2 or more 0
Cnt Ac-S Z pair status 0 1
Cnt Ac-S Z pair status 1 1
Cnt Ac-S Z pair status 2 or more 1
•
Cnt Ac-S Z pair status is reported to the host if you query the Cnt Ac-S Z P-VOL or S-VOL. To
obtain the BC Z pair status, query the BC Z P-VOL pair.
•
BC Z supports multiple S-VOLs for each of its P-VOLs, but when you issue a pair status query,
the status is returned only for the pair whose S-VOL has the lowest LDEV ID. To check pair
status for the other S-VOLs, direct a host query to the specific S-VOL using the S-VOL’s LDEV
ID in the host command.
Remote Web Console displays the status of all S-VOLs.
The following table shows when data is current on a shared Cnt Ac-S Z/BC Z volume based on
the pair statuses.
BC Z pair status Cnt Ac-S Z pair
status
Suspended Resync-R/REVRSY Resync/Pending Split/SUSPOP V-Split/SUSPVS Split/
SUSPOP
Pending Duplex Pending
Not Current - Not Current Current Not Current Not Current Not
Current Not Current Pending
Not Current - Not Current Current Not Current Not Current Not
Current Not Current Duplex
Not Current Current Current Current Current Current Current Not Current Suspend
-S-VOL by
operator/Suspend
Continuous Access Journal Z
Cnt Ac-S Z and Continuous Access Journal Z can share the same pair volumes. Using a combined
Cnt Ac-S Z and Continuous Access Journal Z configuration can extend disaster recovery options
to a third data center.
Like Cnt Ac-S Z, a Continuous Access Journal Z pair maintains a copy of the production volume
in a second location. However, unlike Cnt Ac-S Z, the Continuous Access Journal Z S-VOL is
asynchronous, and the secondary system can be located much greater distances from the local
and remote Cnt Ac-S Z sites.
Creating both a Cnt Ac-S Z and a Continuous Access Journal Z backup ensures that a copy in a
third location is available in the event that the local site or one of the systems fails.
Configurations consisting of Cnt Ac-S Z and Continuous Access Journal Zpair volumes are covered
extensively in the HP XP7 Continuous Access Journal for Mainframe Systems User Guide.
56 Sharing Continuous Access Synchronous Z volumes