IBM System storage DS6000 Series, Redbook

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IBM System Storage DS6000 Series: Copy Services with IBM System z
14.2.4 CDELPAIR
The CDELPAIR command is used to specify the primary and secondary volumes to be
removed from a Metro Mirror pairing. This command should be directed to the primary device;
see Example 14-3.
Example 14-3 CDELPAIR command
CDELPAIR DEVN(X'6400') PRIM(X'0002' AAVCA X'00' X'00') -
SEC(X'0003' AAVCA X'00' X'01')
Before issuing a CDELPAIR command, you should verify that there are some active paths
between the respective primary and secondary LSSs. If all of the paths that were established
between both LSSs have been disabled, the CDELPAIR command will fail. After the failing
CDELPAIR command times out, the state of the primary volume is simplex. The secondary
volume remains in its previous state (duplex, pending, or suspended). You then must issue a
CRECOVER command to return the secondary volume to the simplex state.
In Example 14-3, the primary volume has SSID x’ 0002 ’, the serial number is AAVCA , the CCA
is x’ 00 ’, and the LSS is x’ 00 ’.
14.2.5 CDELPATH
The CDELPATH command is used to delete established Metro mirror paths between a
primary LSS and the corresponding secondary LSS; see Example 14-4. Only the paths to the
specified secondary LSS are affected. All other paths to other LSSs are not affected.
Before issuing a CDELPATH command, a CDELPAIR command to all Metro Mirror volume
pairs should be issued. The CDELPATH command may cause an
ANTP0121I message if this
sequence is not followed.
Example 14-4 CDELPATH command
CDELPATH DEVN(X'6400') PRIM(X'0002' 500507630EFFFCA0 X'00') -
SEC(X'0003' 500507630EFFFCA0 X'01')
In Example 14-4, the primary device has SSID x’
0002
’, WWNN
500507630EFFFCA0
and LSS
x’
00
’.
14.2.6 CGROUP
The CGROUP command is used to control operations for multiple Metro Mirror volume pairs
on a given LSS:
򐂰
CGROUP FREEZE
This command suspends Metro Mirror operations for all Metro Mirror volumes on the
specified LSS pair. With the FREEZE parameter, Metro Mirror volume pairs are
suspended and Metro Mirror paths are deleted for the specified LSS pair. If the Metro
Mirror paths for the LSS pair were defined with Consistency Group enabled (CGROUP
parameter of the CESTPATH command), then an extended long busy (ELB) condition is
initiated when CGROUP FREEZE is issued for the LSS. During the ELB window, update
activity cannot proceed in the LSS where the freeze was done.
򐂰
CGROUP RUN
This command resumes all operations for the Metro Mirror volumes on the specified LSS.
The CGROUPY RUN command is used in order to reset the ELB condition and release
application I/O to the primary volumes.