Comment 35 for bug 1740892

Testing on Trusty:

# apt-get install corosync pacemaker
# Make corosync start at boot
# sed -i 's/no/yes/' /etc/default/corosync
# Make pacemaker start at boot
# update-rc.d pacemaker defaults
# reboot

# service corosync status; service pacemaker status
 * corosync is running
pacemakerd (pid 1927) is running...

Add PPA and upgrade corosync:

# add-apt-repository ppa:nacc/lp1740892
# apt-get update; apt-get install corosync

# service corosync status; service pacemaker status
 * corosync is running
pacemakerd is stopped

So what is in my PPA is not yet a fix and I think I see why:

Preparing to unpack .../corosync_2.3.3-1ubuntu4.1~ppa3_amd64.deb ...
 * Stopping corosync daemon corosync
...
Setting up corosync (2.3.3-1ubuntu4.1~ppa3) ...
Installing new version of config file /etc/init.d/corosync ...
 * Restarting corosync daemon corosync warning [MAIN ] Could not lock memory of service to avoid page faults: Cannot allocate memory (12)

So the postinst change is correct and we now restart corosync instead of start it. However, because the old package's prerm is run, that leads to a stop of corosync which in turn causes pacemaker to exit. When we run our updated init-script, it does not detect that pacemaker is running and so does not restart it.