Executing delta resync

When you specify an S-VOL and suspend (swap suspend) a GAD pair, the GAD S-VOL pair status changes from PAIR to SSWS. After the pair status changes to SSWS, the UR delta resync pair changes to a UR pair, and the copying from the GAD S-VOL to the UR S-VOL starts. This change in the copy source of the UR pair is the delta resync operation.

For details about storage system support (models, microcode) for GAD+UR operations, see the Global-Active Device User Guide.

Before you begin

  • Pair status and mirror status must be as follows:

    Pair type

    Pair status

    Mirror status

    P-VOL

    S-VOL

    Master journal

    Restore journal

    GAD pair

    PAIR

    PAIR

    Not applicable

    Not applicable

    UR pair

    PAIR

    PAIR

    PJNN

    SJNN

    UR delta resync pair

    PSUS*

    SSUS*

    PJNS

    SJNS

    * If you use Device Manager - Storage Navigator to suspend (swap suspend) the pair, make sure the status of the UR delta resync pair is HOLD.

  • All the differential data of the UR pairs is stored in the primary site's journal.
  • Data must be able to be transferred between the UR P-VOL and S-VOL.
  • The number of S-VOLs in the UR pairs is the same as that in the UR delta resync pairs.
  • There is no failure in the remote path between the secondary site of GAD and the secondary site of UR.
  • After creating the UR pair, you must keep updating I/O from the server to the GAD pair's P-VOL or S-VOL for about two minutes.

Command example

pairsplit -g oraHA -RS -IH1