doc/rados/operations/operating.rst
.. index:: systemd; operating a cluster
In all distributions that support systemd (CentOS 7, Fedora, Debian
Jessie 8 and later, and SUSE), systemd files (and NOT legacy SysVinit scripts)
are used to manage Ceph daemons. Ceph daemons therefore behave like any other daemons
that can be controlled by the systemctl command, as in the following examples:
.. prompt:: bash $
sudo systemctl start ceph.target # start all daemons sudo systemctl status ceph-osd@12 # check status of osd.12
To list all of the Ceph systemd units on a node, run the following command:
.. prompt:: bash $
sudo systemctl status ceph*.service ceph*.target
To start all of the daemons on a Ceph node (regardless of their type), run the following command:
.. prompt:: bash $
sudo systemctl start ceph.target
To stop all of the daemons on a Ceph node (regardless of their type), run the following command:
.. prompt:: bash $
sudo systemctl stop ceph*.service ceph*.target
To start all of the daemons of a particular type on a Ceph node, run one of the following commands:
.. prompt:: bash $
sudo systemctl start ceph-osd.target sudo systemctl start ceph-mon.target sudo systemctl start ceph-mds.target
To stop all of the daemons of a particular type on a Ceph node, run one of the following commands:
.. prompt:: bash $
sudo systemctl stop ceph-osd*.service ceph-osd.target sudo systemctl stop ceph-mon*.service ceph-mon.target sudo systemctl stop ceph-mds*.service ceph-mds.target
To start a specific daemon instance on a Ceph node, run one of the following commands:
.. prompt:: bash $
sudo systemctl start ceph-osd@{id} sudo systemctl start ceph-mon@{hostname} sudo systemctl start ceph-mds@{hostname}
For example:
.. prompt:: bash $
sudo systemctl start ceph-osd@1 sudo systemctl start ceph-mon@ceph-server sudo systemctl start ceph-mds@ceph-server
To stop a specific daemon instance on a Ceph node, run one of the following commands:
.. prompt:: bash $
sudo systemctl stop ceph-osd@{id} sudo systemctl stop ceph-mon@{hostname} sudo systemctl stop ceph-mds@{hostname}
For example:
.. prompt:: bash $
sudo systemctl stop ceph-osd@1 sudo systemctl stop ceph-mon@ceph-server sudo systemctl stop ceph-mds@ceph-server
.. index:: sysvinit; operating a cluster
Each time you start, restart, or stop Ceph daemons, you must specify at least one option and one command. Likewise, each time you start, restart, or stop your entire cluster, you must specify at least one option and one command. In both cases, you can also specify a daemon type or a daemon instance. ::
{commandline} [options] [commands] [daemons]
The ceph options include:
+-----------------+----------+-------------------------------------------------+
| Option | Shortcut | Description |
+=================+==========+=================================================+
| --verbose | -v | Use verbose logging. |
+-----------------+----------+-------------------------------------------------+
| --valgrind | N/A | (Dev and QA only) Use Valgrind_ debugging. |
+-----------------+----------+-------------------------------------------------+
| --allhosts | -a | Execute on all nodes listed in ceph.conf. |
| | | Otherwise, it only executes on localhost. |
+-----------------+----------+-------------------------------------------------+
| --restart | N/A | Automatically restart daemon if it core dumps. |
+-----------------+----------+-------------------------------------------------+
| --norestart | N/A | Do not restart a daemon if it core dumps. |
+-----------------+----------+-------------------------------------------------+
| --conf | -c | Use an alternate configuration file. |
+-----------------+----------+-------------------------------------------------+
The ceph commands include:
+------------------+------------------------------------------------------------+
| Command | Description |
+==================+============================================================+
| start | Start the daemon(s). |
+------------------+------------------------------------------------------------+
| stop | Stop the daemon(s). |
+------------------+------------------------------------------------------------+
| forcestop | Force the daemon(s) to stop. Same as kill -9. |
+------------------+------------------------------------------------------------+
| killall | Kill all daemons of a particular type. |
+------------------+------------------------------------------------------------+
| cleanlogs | Cleans out the log directory. |
+------------------+------------------------------------------------------------+
| cleanalllogs | Cleans out everything in the log directory. |
+------------------+------------------------------------------------------------+
The [daemons] option allows the ceph service to target specific daemon types
in order to perform subsystem operations. Daemon types include:
monosdmds.. _Valgrind: http://www.valgrind.org/ .. _initctl: http://manpages.ubuntu.com/manpages/raring/en/man8/initctl.8.html