Hitachi ShadowImage for IBM z/OS User"s Guide (T5213-96002, June 2007)

2-16 About ShadowImage™ for IBM
®
z/OS
®
Operations
Hitachi ShadowImage™ for IBM
®
z/OS
®
User’s Guide
1. If a volume is not assigned to an SIz pair, its status is simplex.
2. Select the simplex volumes for S-VOL and T-VOL to create an SIz pair.
When you create an SIz pair, the initial copy operation starts. During the
initial copy operation, the status of the S-VOL and T-VOL changes to
pending.
3. When the initial copy operation is complete, the pair status becomes
duplex. When the initial copy is completed, the differential data between
the S-VOL and the T-VOL will be copied by the update copy.
4. There are two kinds of pair status (split and suspend) when the pair is not
synchronized.
– When you split a pair (pairsplit), the pair status changes to split.
– During the pairsplit process, the pair status becomes SP-pending. Note
that if you specify Quick Split pairsplit, the pair status becomes V-Split
during the process. When the split is complete, the pair status changes
to split, and you can access the split T-VOL. The update copy operation
is not performed on the pairs which status is split.
– If the USP V cannot maintain duplex status for any reason, or if you
suspend the pair, the pair status changes to suspend.
5. When you start a pairresync operation, the pair status changes to resync or
resync-r. When the pairresync operation is complete, the pair status
changes to PAIR.
Notes:
– 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 details on the
settings of the pairresync operation, see section Suspend Pair
Operation.
– When you delete a pair, the status of the volumes that were used by
that pair changes to simplex. Note that you cannot delete the pair
which status is V-Split.
Table 2-1 lists and describes the SIz pair status conditions.
Table 2-1 ShadowImage for z/OS Pair Status
Status Description Host Status S-VOL Access
T-VOL Access
Simple
x
The volume is not assigned to an SIz pair.
The USP V storage system 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 (there is
no T-VOL yet).
If the volume is reserved
as a T-VOL, the storage
system does not accept
read and write I/Os.
Pendin
g
The initial copy operation is in progress. No
update copy operations are performed.
S-VOL = PPRI-
PNDG
T-VOL = PSEC-
PNDG
Read/write-
enabled
Read/write- disabled