Adding a monitor
----------------
-1) Initialize the new monitor's data directory with the ``ceph-mon
---mkfs`` command. You need to provide the new monitor with three
-pieces of information:
+#. Initialize the new monitor's data directory with the ``ceph-mon
+ --mkfs`` command. You need to provide the new monitor with three
+ pieces of information:
- the cluster fsid
- one or more existing monitors to join
The simplest way to do this is probably::
- $ ceph mon getmap -o /tmp/monmap
- $ ceph auth export mon. -o /tmp/monkey
+ $ ceph mon getmap -o /tmp/monmap # provides fsid and existing monitor addrs
+ $ ceph auth export mon. -o /tmp/monkey # mon. auth key
$ ceph-mon -i newname --mkfs --monmap /tmp/foo --keyring /tmp/monkey
-2) Start the new monitor and it will automatically join the cluster::
+#. Start the new monitor and it will automatically join the cluster::
- $ ceph-mon -i newname
-
-3) If you would like other nodes to be able to use this monitor during
-their initial startup, you'll need to adjust ``ceph.conf`` to add a
-section and ``mon addr`` for the new monitor, or add it to the
-existing ``mon host`` list.
+ $ ceph-mon -i newname
+#. If you would like other nodes to be able to use this monitor during
+ their initial startup, you'll need to adjust ``ceph.conf`` to add a
+ section and ``mon addr`` for the new monitor, or add it to the
+ existing ``mon host`` list.
Removing a monitor from a healthy cluster
-----------------------------------------
The mon cluster may not be up because you have lost too many nodes to
form a quorum.
-1) On a surviving monitor node, find the most recent monmap::
+#) On a surviving monitor node, find the most recent monmap::
$ ls $mon_data/monmap
1 2 accepted_pn last_committed latest
in this case it is 2.
-2) Copy to a temporary location and modify the monmap to remove the
-node(s) you don't want. Let's say the map has ``mon.a``, ``mon.b``,
-and ``mon.c``, but only ``mon.a`` is surviving::
+#) Copy to a temporary location and modify the monmap to remove the
+ node(s) you don't want. Let's say the map has ``mon.a``, ``mon.b``,
+ and ``mon.c``, but only ``mon.a`` is surviving::
$ cp $mon_data/monmap/2 /tmp/foo
$ monmaptool /tmp/foo --rm b
$ service ceph stop mon
4) Inject the modified map on any surviving nodes. For example, for
-``mon.a``::
+ ``mon.a``::
$ ceph-mon -i a --inject-monmap /tmp/foo # for each surviving monitor
$ service ceph start mon # on each node with a surviving monitor
6) Remove the old monitors from ``ceph.conf`` so that nobody tries to
-connect to the old instances.
\ No newline at end of file
+ connect to the old instances.
\ No newline at end of file