If you use the intersystem link for host traffic, ensure that you have sufficient
bandwidth to support all sources of load.
Scenario: The hosts in a local clustered
system can read and write
to the volumes in a remote system
In this scenario, the hosts in the local system also exchange heartbeats with the hosts that are
in the remote system. Because the intersystem link is being used for multiple purposes, you must
have sufficient bandwidth to support the following sources of load:
- Global Mirror or Metro Mirror data transfers and the
system heartbeat traffic.
- Local host to remote volume I/O traffic or remote host to local
volume I/O traffic.
- Local-host-to-remote-host heartbeat traffic. If the local host to remote
volume I/O traffic is allowed to use a high percentage of intersystem link
bandwidth, the latency that is seen by the hosts that access system volumes that
are participating in Metro Mirror or Global Mirror operations can be
impacted. The bandwidth congestion can cause the Global Mirror link tolerance
threshold to be exceeded. When the Global Mirror link tolerance
threshold is exceeded, Global Mirror relationships are
stopped.