As per nacc's comment it seems like "Wants=" is the recommended way to hook start-up of one unit to the start-up of another unit.[1]
[1] - https://www.freedesktop.org/software/systemd/man/systemd.unit.html#Wants= So far I have tested using 2 scenarios (including "Wants=pacemaker.service") and it look good so far. --------------------------------------- * Scenario #1 [Both corosync & pacemaker installed] --------------------------------------- - pacemaker start on corosync start. root@xenialcorosyncpacemaker:~# systemctl status corosync | egrep "PID|Active:" Active: active (running) since Mon 2018-01-08 19:29:44 UTC; 21s ago Main PID: 445 (corosync) root@xenialcorosyncpacemaker:~# systemctl status pacemaker | egrep "PID|Active:" Active: active (running) since Mon 2018-01-08 19:29:44 UTC; 27s ago Main PID: 447 (pacemakerd) root@xenialcorosyncpacemaker:~# systemctl stop corosync root@xenialcorosyncpacemaker:~# systemctl status corosync | egrep "PID|Active:" Active: inactive (dead) since Mon 2018-01-08 19:30:29 UTC; 1s ago Main PID: 445 (code=exited, status=0/SUCCESS) root@xenialcorosyncpacemaker:~# systemctl status pacemaker | egrep "PID|Active:" Active: inactive (dead) since Mon 2018-01-08 19:30:29 UTC; 3s ago Main PID: 447 (code=exited, status=0/SUCCESS) root@xenialcorosyncpacemaker:~# systemctl start corosync root@xenialcorosync:~# systemctl status corosync | egrep "PID|Active:" Active: active (running) since Mon 2018-01-08 19:30:56 UTC; 1s ago Main PID: 474 (corosync) root@xenialcorosyncpacemaker:~# systemctl status pacemaker | egrep "PID|Active:" Active: active (running) since Mon 2018-01-08 19:30:56 UTC; 3s ago Main PID: 476 (pacemakerd) --------------------------------------- * Scenario #2 [corosync installed & pacemaker not installed] --------------------------------------- - It doesn't seem to have any side-effects when pacemaker isn't installed. The Wants= options is simply ignore since the pacemaker.service is not present. root@xenialcorosyncnopacemaker:~# systemctl status corosync | egrep "PID|Active:" Active: active (running) since Mon 2018-01-08 19:32:11 UTC; 53s ago Main PID: 1284 (corosync) root@xenialcorosyncnopacemake:~# systemctl status pacemaker ● pacemaker.service Loaded: not-found (Reason: No such file or directory) Active: inactive (dead) root@v:~# systemctl stop corosync root@xenialcorosyncnopacemake:~# systemctl status pacemaker ● pacemaker.service Loaded: not-found (Reason: No such file or directory) Active: inactive (dead) root@xenialcorosyncnopacemake:~# systemctl status corosync | egrep "PID|Active:" Active: inactive (dead) since Mon 2018-01-08 19:33:17 UTC; 4s ago Main PID: 1284 (code=exited, status=0/SUCCESS) root@xenialcorosyncnopacemake:~# systemctl start corosync root@xenialcorosyncnopacemake:~# systemctl status corosync | egrep "PID|Active:" Active: active (running) since Mon 2018-01-08 19:33:26 UTC; 1s ago Main PID: 1378 (corosync) - Eric -- You received this bug notification because you are a member of Ubuntu High Availability Team, which is subscribed to pacemaker in Ubuntu. https://bugs.launchpad.net/bugs/1740892 Title: corosync upgrade on 2018-01-02 caused pacemaker to fail Status in OpenStack hacluster charm: Invalid Status in corosync package in Ubuntu: In Progress Status in pacemaker package in Ubuntu: New Bug description: During upgrades on 2018-01-02, corosync and it's libs were upgraded: (from a trusty/mitaka cloud) Upgrade: libcmap4:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4), corosync:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4), libcfg6:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4), libcpg4:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4), libquorum5:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4), libcorosync-common4:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4), libsam4:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4), libvotequorum6:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4), libtotem-pg5:amd64 (2.3.3-1ubuntu3, 2.3.3-1ubuntu4) During this process, it appears that pacemaker service is restarted and it errors: syslog:Jan 2 16:09:33 juju-machine-0-lxc-4 pacemakerd[1994]: notice: crm_update_peer_state: pcmk_quorum_notification: Node juju-machine-1-lxc-3[1001] - state is now lost (was member) syslog:Jan 2 16:09:34 juju-machine-0-lxc-4 pacemakerd[1994]: notice: crm_update_peer_state: pcmk_quorum_notification: Node juju-machine-1-lxc-3[1001] - state is now member (was lost) syslog:Jan 2 16:14:32 juju-machine-0-lxc-4 pacemakerd[1994]: error: cfg_connection_destroy: Connection destroyed syslog:Jan 2 16:14:32 juju-machine-0-lxc-4 pacemakerd[1994]: notice: pcmk_shutdown_worker: Shuting down Pacemaker syslog:Jan 2 16:14:32 juju-machine-0-lxc-4 pacemakerd[1994]: notice: stop_child: Stopping crmd: Sent -15 to process 2050 syslog:Jan 2 16:14:32 juju-machine-0-lxc-4 pacemakerd[1994]: error: pcmk_cpg_dispatch: Connection to the CPG API failed: Library error (2) syslog:Jan 2 16:14:32 juju-machine-0-lxc-4 pacemakerd[1994]: error: mcp_cpg_destroy: Connection destroyed Also affected xenial/ocata To manage notifications about this bug go to: https://bugs.launchpad.net/charm-hacluster/+bug/1740892/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-ha Post to : [email protected] Unsubscribe : https://launchpad.net/~ubuntu-ha More help : https://help.launchpad.net/ListHelp
