Hitachi ShadowImage for z/OS user guide (HIT9503-96004, June 2006)

ShadowImage for z/OS user guide 87

Table 33 describes ShadowImage - FlashCopy pair status condition.

Establishing ShadowImage - FlashCopy Pairs

You can establish an ShadowImage - FlashCopy pair for an SI390 simplex volume. Table 34 shows the

allowable ShadowImage - FlashCopy operations for each pair status. You can also add an ShadowImage

- FlashCopy pair for SI390 S-VOL or T-VOL in the split or duplex status (see Table 35 and Table 36).

However, you cannot establish a ShadowImage - FlashCopy pair if the S-VOL already has three T-VOLs.

ShadowImage - FlashCopy adds a second layer of ShadowImage - FlashCopy pairs onto the first layer of

original SI390 pairs. These two layers of pairs (L1 and L2) can create up to six copies of one original

SI390 source volume (S-VOL).

NOTE: You cannot add an ShadowImage - FlashCopy L2 pair onto an ShadowImage - FlashCopy L1

pair, an SI390 L2 pair onto an SI390 L1 pair, or any third layer of pair (L3 pair) onto an L2 pair.

Table 33 ShadowImage - FlashCopy pair status condition

Status Description Host Status S-VOL Access T-VOL Access

F-Copy ShadowImage - FlashCopy is

requested with host commands. The

S-VOL differential data is copied to the

T-VOL in the background. When the

NOCOPY option is specified, no

background copy is performed.

S-VOL = SIMPLEX

T-VOL = SIMPLEX

Read/write. Read/write, can

be varied online.

Table 34 Pair Status versus allowable operations

Operation Pair Status

SI390 SI -

Simpl. Pend. Dupl. SP-

Pend

V-

Spl.

Spl. Resync Resync-

Susp. F-

Copy

Split Pair OK OK OK x x x x x x x

Suspend Pair x OK OK OK OKOKOK x OK x

Resync Pair x x x x OK OK x x OK x

Reverse Copy x x x x x OK x x x x

Quick Restorex xxxxOKx x xx

Delete Pair x OK OK OK x OK OK OK OK OK

Establish

Relationship

OK x x x xxx x x x

Withdraw

Relationship

x x x x xxx x x OK