Monitor commands

From Ceph wiki

Monitor commands are issued using the ceph utility(in versions before Dec08 it was called cmonctl):

$ ceph [-m monhost] command

where the command is usually of the form

$ ceph subsystem command

[edit] System commands

$ ceph stop

Cleanly shut down the file system.

[edit] OSD subsystem

[edit] stat

$ ceph osd stat

Query osd subsystem status.

[edit] getmap

$ ceph osd getmap -o file

Write a copy of the most recent osd map to a file. See osdmaptool.

[edit] getcrushmap

$ ceph osd getcrushmap -o file

Write a copy of the crush map from the most recent osd map to file. This is functionally equivalent to

$ ceph osd getmap -o /tmp/osdmap
$ osdmaptool /tmp/osdmap --export-crush file

[edit] getmaxosd

$ ceph osd getmaxosd

Query the current max_osd parameter in the osd map.

[edit] setmap

$ ceph osd setmap -i file

Import the given osd map. Note that this can be a bit dangerous, since the osd map includes dynamic state about which OSDs are current on or offline; only do this if you've just modified a (very) recent copy of the map.

[edit] setcrushmap

$ ceph osd setcrushmap -i file

Import the given crush map.

[edit] setmaxosd

$ ceph osd setmaxosd

Set the max_osd parameter in the osd map. This is necessary when expanding the storage cluster.

[edit] down

$ ceph osd down N

Mark osdN down.

[edit] out

$ ceph osd out N

Mark osdN out of the distribution (i.e. allocated no data).

[edit] in

$ ceph osd in N

Mark osdN in the distribution (i.e. allocated data);

[edit] MDS subsystem

[edit] stat

[edit] dump

[edit] getmap

[edit] stop

[edit] set_max_mds

[edit] setmap