From bae4b3223764d284e27387ba494920e2f8ddcc91 Mon Sep 17 00:00:00 2001 From: Iustin Pop <iustin@google.com> Date: Sat, 13 Nov 2010 20:14:32 +0100 Subject: [PATCH] Add RST version of ganeti-watcher man page MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Iustin Pop <iustin@google.com> Reviewed-by: RenΓ© Nussbaumer <rn@google.com> --- man/ganeti-watcher.rst | 76 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 man/ganeti-watcher.rst diff --git a/man/ganeti-watcher.rst b/man/ganeti-watcher.rst new file mode 100644 index 000000000..cc38a83cb --- /dev/null +++ b/man/ganeti-watcher.rst @@ -0,0 +1,76 @@ +ganeti-watcher(8) Ganeti | Version @GANETI_VERSION@ +=================================================== + +Name +---- + +ganeti-watcher - Ganeti cluster watcher + +Synopsis +-------- + +**ganeti-watcher** [``--debug``] +[``--job-age=``*age*] +[``--ignore-pause``] + +DESCRIPTION +----------- + +The **ganeti-watcher** is a periodically run script which is +responsible for keeping the instances in the correct status. It has +two separate functions, one for the master node and another one +that runs on every node. + +If the watcher is disabled at cluster level (via the +**gnt-cluster watcher pause** command), it will exit without doing +anything. The cluster-level pause can be overriden via the +``--ignore-pause`` option, for example if during a maintenance the +watcher needs to be disabled in general, but the administrator +wants to run it just once. + +The ``--debug`` option will increase the verbosity of the watcher +and also activate logging to the standard error. + +Master operations +~~~~~~~~~~~~~~~~~ + +Its primary function is to try to keep running all instances which +are marked as *up* in the configuration file, by trying to start +them a limited number of times. + +Another function is to "repair" DRBD links by reactivating the +block devices of instances which have secondaries on nodes that +have been rebooted. + +The watcher will also archive old jobs (older than the age given +via the ``--job-age`` option, which defaults to 6 hours), in order +to keep the job queue manageable. + +Node operations +~~~~~~~~~~~~~~~ + +The watcher will restart any down daemons that are appropriate for +the current node. + +In addition, it will execute any scripts which exist under the +"watcher" directory in the Ganeti hooks directory +(``@SYSCONFDIR@/ganeti/hooks``). This should be used for lightweight +actions, like starting any extra daemons. + +If the cluster parameter ``maintain_node_health`` is enabled, then the +watcher will also shutdown instances and DRBD devices if the node is +declared as offline by known master candidates. + +The watcher does synchronous queries but will submit jobs for +executing the changes. Due to locking, it could be that the jobs +execute much later than the watcher submits them. + +FILES +----- + +The command has a state file located at +``@LOCALSTATEDIR@/lib/ganeti/watcher.data`` (only used on the master) +and a log file at ``@LOCALSTATEDIR@/log/ganeti/watcher.log``. Removal +of either file will not affect correct operation; the removal of the +state file will just cause the restart counters for the instances to +reset to zero. -- GitLab