Operating a Cluster

Running Ceph with systemd

For all distributions that support systemd (CentOS 7, Fedora, DebianJessie 8 and later, SUSE), ceph daemons are now managed using nativesystemd files instead of the legacy sysvinit scripts. For example:

sudo systemctl start ceph.target       # start all daemons
sudo systemctl status ceph-osd@12      # check status of osd.12

To list the Ceph systemd units on a node, execute:

sudo systemctl status ceph\*.service ceph\*.target

Starting all Daemons

To start all daemons on a Ceph Node (irrespective of type), execute thefollowing:

sudo systemctl start ceph.target

Stopping all Daemons

To stop all daemons on a Ceph Node (irrespective of type), execute thefollowing:

sudo systemctl stop ceph\*.service ceph\*.target

Starting all Daemons by Type

To start all daemons of a particular type on a Ceph Node, execute one of thefollowing:

sudo systemctl start ceph-osd.target
sudo systemctl start ceph-mon.target
sudo systemctl start ceph-mds.target

Stopping all Daemons by Type

To stop all daemons of a particular type on a Ceph Node, execute one of thefollowing:

sudo systemctl stop ceph-mon\*.service ceph-mon.target
sudo systemctl stop ceph-osd\*.service ceph-osd.target
sudo systemctl stop ceph-mds\*.service ceph-mds.target

Starting a Daemon

To start a specific daemon instance on a Ceph Node, execute one of thefollowing:

sudo systemctl start ceph-osd@{id}
sudo systemctl start ceph-mon@{hostname}
sudo systemctl start ceph-mds@{hostname}

For example:

sudo systemctl start ceph-osd@1
sudo systemctl start ceph-mon@ceph-server
sudo systemctl start ceph-mds@ceph-server

Stopping a Daemon

To stop a specific daemon instance on a Ceph Node, execute one of thefollowing:

sudo systemctl stop ceph-osd@{id}
sudo systemctl stop ceph-mon@{hostname}
sudo systemctl stop ceph-mds@{hostname}

For example:

sudo systemctl stop ceph-osd@1
sudo systemctl stop ceph-mon@ceph-server
sudo systemctl stop ceph-mds@ceph-server

Starting all Daemons

To start all daemons on a Ceph Node (irrespective of type), execute thefollowing:

sudo start ceph-all

Stopping all Daemons

To stop all daemons on a Ceph Node (irrespective of type), execute thefollowing:

sudo stop ceph-all

Starting all Daemons by Type

To start all daemons of a particular type on a Ceph Node, execute one of thefollowing:

sudo start ceph-osd-all
sudo start ceph-mon-all
sudo start ceph-mds-all

Stopping all Daemons by Type

To stop all daemons of a particular type on a Ceph Node, execute one of thefollowing:

sudo stop ceph-osd-all
sudo stop ceph-mon-all
sudo stop ceph-mds-all

Starting a Daemon

To start a specific daemon instance on a Ceph Node, execute one of thefollowing:

sudo start ceph-osd id={id}
sudo start ceph-mon id={hostname}
sudo start ceph-mds id={hostname}

For example:

sudo start ceph-osd id=1
sudo start ceph-mon id=ceph-server
sudo start ceph-mds id=ceph-server

Stopping a Daemon

To stop a specific daemon instance on a Ceph Node, execute one of thefollowing:

sudo stop ceph-osd id={id}
sudo stop ceph-mon id={hostname}
sudo stop ceph-mds id={hostname}

For example:

sudo stop ceph-osd id=1
sudo start ceph-mon id=ceph-server
sudo start ceph-mds id=ceph-server

Running Ceph

Each time you to start, restart, and stop Ceph daemons (or yourentire cluster) you must specify at least one option and one command. You mayalso specify a daemon type or a daemon instance.

{commandline} [options] [commands] [daemons]

The ceph options include:

The ceph commands include:

For subsystem operations, the ceph service can target specific daemon typesby adding a particular daemon type for the [daemons] option. Daemon typesinclude:

• mon

• osd

• mds