Consistency Group And Critical Mode Combination; Metro Mirror Paths And Links - IBM System storage DS6000 Series Redbook

The volume pair is suspended and further writes to the source volume are not accepted if
data cannot be sent to the target volume.

13.3.5 Consistency Group and critical mode combination

Table 13-1 shows what happens when the CRIT parameter of the CESTPAIR command, and
the CGROUP parameter of CESTPATH command are combined. These options can also be
set using the DS CLI, or with the DS Storage Manager GUI.
Table 13-1 Interaction of CRIT and CGROUP parameters
CGROUP(Y)
CGROUP(N)
The IEA494I message with SUSPENDED status is issued for the in-error pair to all z/OS images
that have the primary volume online. An IEA491E message is returned to the issuing system
of the next I/O that is attempted to the volume that is suspended. For open systems, an
SNMP trap will be issued to the address specified when the DS6000 SNMP service was
configured.
For further discussion on the CGROUP and the CRIT parameters, refer to z/OS DFSMS
Advanced Copy Services, SC35-0428.

13.4 Metro Mirror paths and links

Metro Mirror pairs are set up between volumes in LSSs, usually in different disk subsystems,
and these are normally in separate locations. A
between the primary (source) LSS and the secondary (target) LSS. These
defined over
The physical link includes the host adapter in the primary DS6000, the cabling, switches or
directors, any wideband or long distance transport devices (DWDM, channel extenders,
WAN), and the host adapters in the secondary disk subsystem. Physical links can carry
multiple Metro Mirror logical paths, as shown in Figure 13-5 on page 143.
Note: For Metro Mirror, the DS6000 supports Fibre Channel links only. To facilitate ease of
testing, the DS6000 does support Metro Mirror source and target on the same DS6000.
142
IBM System Storage DS6000 Series: Copy Services with IBM System z
CRIT(Y)
IEA494I with long busy state
(SNMP trap for open systems)
Pair in error suspended
Unit check on primary device
IEA494I when suspended
No long busy state
Pair in error suspended
Unit check on primary device
IEA494I when suspended
physical links
between the disk subsystems.
CRIT(N)
IEA494I with long busy state
(SNMP trap for open systems)
Pair in error suspended
No unit check on primary device
IEA494I when suspended
No long busy state
Pair in error suspended
No unit check on primary device
IEA494I when suspended
path
(or group of paths) needs to be defined
logical paths
are