Hitachi ShadowImage for z/OS user guide (December 2005)

32 ShadowImage for the XP128/XP1024/XP10000/XP12000
NOTE: When you specify reverse or quick restore mode for a pairresync operation, the pair status
changes to resync-r (data is copied in the reverse direction from the T-VOL to the S-VOL). For more
information about pairresync operation settings, see ”Resynchronizing ShadowImage Pairs” on page 57.
When you delete a pair, the pair status changes to simplex. You cannot delete the pair with status V-Split.
Table 7 shows the allowable operations for each pair status. Table 8 lists and describes the SI390 pair
status conditions.
Table 7 Pair status versus allowable operations
Operation Pair Status
Simplex Pending Duplex SP-
Pend
V-
Split
Split Resync Resync-R Suspend
Add Pair OK x x x x x x x x
Split Pair OK OK OK x x x x x x
Suspend Pair x OK OK OK OKOKOK OK x
Resync Pair x x x x OK OK x x OK
Reverse Resync
Quick Restore
xxxxxOKxx x
Delete Pair x OK OK OK x OK OK OK OK
Table 8 ShadowImage for z/OS pair status
Status Description Host Status S-VOL Access T-VOL Access
Simplex The volume is not assigned to an SI390 pair.
The XP128/XP1024/XP10000/XP12000
accepts read and write I/Os for all simplex
volumes that are not reserved.
S-VOL = SIMPLEX
T-VOL = SIMPLEX
N/A
There is no
S-VOL yet.
N/A
If the volume is
reserved as a
T-VOL, the disk
array does not
accept read
and write I/Os.
Pending The initial copy operation is in progress. The
XP128/XP1024/XP10000/XP12000
continues to accept read and write
operations for the S-VOL, but stops accepting
writes for the T-VOL. No update copy
operations are performed.
S-VOL = PPRI-PNDG
T-VOL = PSEC-PNDG
Read/write. Read/write
disabled.
Duplex The initial copy operation is complete and
the XP128/XP1024/XP10000/XP12000
starts performing asynchronous update copy
operations from the S-VOL to the T-VOL as
needed. The S-VOL and T-VOL of a duplex
pair may not be identical. The
XP128/XP1024/XP10000/XP12000 rejects
all write I/Os for T-VOLs with the status
duplex.
S-VOL = PPRIMARY
T-VOL = PSECONDRY
Read/write. Read/write
disabled.