IBM System storage DS6000 Series, Redbook

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Chapter 26. Global Mirror examples
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Figure 26-6 summarizes the scenario. The numbers indicate the sequence of events and
main considerations, and also relate to Figure 26-7 where the corresponding ICKDSF
commands are shown.
The sequence of steps for a Global Mirror planned outage is as follows:
1. Pause the Global Mirror session.
2. Suspend Global Copy pairs.
3. Application I/O continues all the time.
4. Failover from B to A. This turns the B volumes into Global Copy primary suspended.
5. Create a data consistent set of B volumes. This is done with a Fast Reverse Restore
(FRR) from the C to the B volumes.
6. Reestablish Global Mirror FlashCopy relationships from B to C. Both volumes are identical
afterwards.
7. Optionally create a data consistent set of D volumes.
8. Use the D volumes for test or other purposes.
9. In order to prepare and continue with Global Mirror, apply the changes that were
accumulated at the local site from the A volumes to the B volumes. This is done with a
Failback operation with the A volumes as primary and the B volumes as secondary.
10.Resume Global Mirror.
Figure 26-7 shows the corresponding ICKDSF commands for each step of the procedure.
Figure 26-7 ICKDSF command sequence for Global Mirror planned outage
Note that in most command examples ICKDSF refers to a corresponding JCL DD statement
through the DDNAME parameter. This DD statement points to the LSS or volume.
(1) Pause session
PPRCOPY DDNAME( DD01) TMASYNC -
SESSNO( 001) -
PAUSE -
MASTER
PPRCOPY DDNAME( DD01) SUSPEND -
LSS( X' 05' X' 00' ) -
PRI ( X' E500' 27310 X' 00' ) -
SEC( X' 7000' 22399 X' 00' )
PPRCOPY UNI T ( 7000) ESTPAI R -
FAI LOVER -
PRI ( X' 7000' 22399 X' 00' ) -
SEC( X' E500' 27310 X' 00' ) -
LSS( X' 00' , X' 05' ) -
OPTI ON( XD)
FC UNI T( 7100) ESTABLI SH / * C VOLUME * / -
TARGETVOL( X' 00' , X' 00' , 7000) / * B VOLUME * / -
FASTREVERSERESTORE / * REVERSE DI RECTI ON * / -
MODE ( COPY) / * START BACKGROUNDCOPY * / -
ONLI NTGT ( YES) -
TGTOKPRI M ( YES) -
TGTCANCOMEONLI NE ( NO)
(2) Suspend all XD pairs
(4) FAILOVER B->A
(5) Fast Reverse restore, FRR
(6) FlashCopy B->C Start Change Recording
FC UNI T( 7000) ESTABLI SH -
TARGETVOL ( X' 01' , X' 00' , 7100) -
CHRCD ( YES) / * CHANGE RECORDI NG * / -
NOTGTWR ( YES) / * I NHI BI T TARGET WRI TES * / -
MODE ( NOCOPY) / * NO BACKGROUND COPY * / -
ONLI NTGT ( YES) -
TGTCANCOMEONLI NE ( NO)
FC UNI T( 7000) ESTABLI SH / * B VOLUME * / -
TARGETVOL ( X' 01' , X' 10' , 7110) / * D VOLUME * / -
ONLI NTGT ( YES) -
TGTCANCOMEONLI NE ( NO)
(7) Flashcopy B -> D
PPRCOPY DDNAME( DD01) ESTPAI R / * A VOLUME * / -
FAI LBACK -
PRI ( X' E500' 27310 X' 00' ) / * A VOLUME * / -
SEC ( X' 7000' 22399 X' 00' ) / * B VOLUME * / -
LSS ( X' 05' , X' 00' ) -
OPTI ON ( XD)
(9) FAILBACK (A=Primary, B=Secondary)
(10) Resume session
PPRCOPY DDNAME( DD01) STASYNC -
MODI FY -
SESSNO( 001) -
CGI T( 0) -
MXCT( 3) -
MXDT( 030)