While the cluster is running, all EMC Symmetrix disk arrays
that belong to the same MC/ServiceGuard package, and are defined
in a single SRDF group must be in the same
state at the same time. Manual changes of these states can cause
the package to halt due to unexpected conditions. In general, it
is recommended that no manual change of states
be performed while the package and the cluster are running.
There might be situations when the package has to be taken
down for maintenance purposes without having the package move to
another node.
The following procedure is recommended for normal maintenance
of the MetroCluster with EMC SRDF:
Stop the package with the appropriate
MC/ServiceGuard command.
# cmhaltpkg pkgname
Split the logical SRDF links for the package.
# Samples/pre.cmquery
Distribute the MetroCluster with EMC SRDF configuration
changes.
# cmapplyconf -P pkgconfig
Restore the logical SRDF links for the package.
# Samples/post.cmapply
Start the package with the appropriate MC/ServiceGuard
command:
# cmmodpkg -e pkgname
No checking of the status of the SA/FA ports is done. It is
assumed that at least one PVLink is functional. Otherwise, the VG
activation will fail.
Planned maintenance is treated the same as a failure by the
cluster. If you take a node down for maintenance, package failover
and quorum calculation is based on the remaining nodes. Make sure
that nodes are taken down evenly at each site, and that enough nodes
remain on-line to form a quorum if a failure occurs. See “Example
Failover Scenarios with Two Arbitrators”.
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