[ClusterLabs] Coming in Pacemaker 1.1.17: start a node in standby

[Ken Gaillot]

Hi all,

Pacemaker 1.1.17 will have a feature that people have occasionally asked
for in the past: the ability to start a node in standby mode.

It will be controlled by an environment variable (set in
/etc/sysconfig/pacemaker, /etc/default/pacemaker, or wherever your
distro puts them):


# By default, nodes will join the cluster in an online state when they first
# start, unless they were previously put into standby mode. If this
variable is
# set to "standby" or "online", it will force this node to join in the
# specified state when starting.
# (experimental; currently ignored for Pacemaker Remote nodes)
# PCMK_node_start_state=default


As described, it will be considered experimental in this release, mainly
because it doesn't work with Pacemaker Remote nodes yet. However, I
don't expect any problems using it with cluster nodes.

Example use cases:

You want want fenced nodes to automatically start the cluster after a
reboot, so they contribute to quorum, but not run any resources, so the
problem can be investigated. You would leave
PCMK_node_start_state=standby permanently.

You want to ensure a newly added node joins the cluster without problems
before allowing it to run resources. You would set this to "standby"
when deploying the node, and remove the setting once you're satisfied
with the node, so it can run resources at future reboots.

You want a standby setting to last only until the next boot. You would
set this permanently to "online", and any manual setting of standby mode
would be overwritten at the next boot.

Many thanks to developers Alexandra Zhuravleva and Sergey Mishin, who
contributed this feature as part of a project with EMC.
-- 
Ken Gaillot <kgaillot at redhat.com>