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

About ShadowImage™ for IBM
®
z/OS
®
Operations 2-17
Hitachi ShadowImage™ for IBM
®
z/OS
®
User’s Guide
Status Description Host Status S-VOL Access
T-VOL Access
Duplex The initial copy operation is complete, and
the USP V storage system 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.
S-VOL = PPRIMARY
T-VOL =
PSECONDRY
Read/write-
enabled
Read/write- disabled
SP-
Pend
The status becomes SP-Pend when the
Steady Split mode is selected for the split
operation. All S-VOL updates prior to the
split command are being copied to the T-
VOL. When these updates are complete, the
split T-VOL is identical to the state of the S-
VOL when the split started.
S-VOL = PPRI-
PNDG
T-VOL = PSEC-
PNDG
Read/write-
enabled
Read/write- disabled
V-Split The status becomes V-Split when the Quick
Split mode is selected for the split operation.
Only the S-VOL differential data is being
copied to the T-VOL in background. The V-
Split pairs cannot be deleted.
S-VOL = PPRI-
SUSP
T-VOL = SIMPLEX
Read/write-
enabled
Read/write-enabled, can
be varied online.
Split The USP V storage system stops performing
update copy operations for split pairs, and
starts accepting write I/Os for split T-VOLs.
The storage system keeps track of all
updates to the split S-VOL and T-VOL, so the
pair can be resynchronized accurately and
quickly.
S-VOL = PPRI-
SUSP
T-VOL = SIMPLEX
Read/write-
enabled
Read/write-enabled, can
be varied online.
Resync When a split pair is resynchronized in normal
mode, only the S-VOL differential data is
copied to the T-VOL. When a suspended pair
is resynchronized, the entire S-VOL is copied
to the T-VOL. No update copy operations are
performed during resync operation.
S-VOL = PPRI-
PNDG
T-VOL = PSEC-
PNDG
Read/write-
enabled
Read/write- disabled
Resync
-R
When a split pair is reverse resynchronized,
the USP V storage system copies only the T-
VOL differential data to the S-VOL. The
reverse copy cannot be performed on
suspended pairs. No update copy operations
are performed during reverse copy or quick
restore.
S-VOL = PPRI-
PNDG
T-VOL = PSEC-
PNDG
Read/write-
disabled
Read/write- disabled
Suspen
d
The USP V storage system does not perform
update copy operations to a suspended T-
VOL. The storage system marks the entire
S-VOL track map as differential data, so the
entire S-VOL is copied to the T-VOL when
the pair is resumed. Use resync command to
resume a suspended pair. Reverse copy and
quick restore cannot be used to resume
suspended pairs.
S-VOL = PPRI-
SUSP
T-VOL = PSEC-
SUSP
Read/write-
enabled
Read/write- disabled
Caution: When you execute DEVSERVE to a read/write disabled volume in
Table 2-1, “INTERVENTION REQUIRED” will be returned. However, when you
create pairs with the volumes online, and when you execute DESERVE to a
read/write disabled volume, a normal value will be returned instead of
“INTERVENTION REQUIRED”. Table 2-2 shows the allowable operations for
each pair status.