The following commands are required to start, stop, or restart Ceph services. Restarting Ceph services is helpful for troubleshoot issues with the utility storage platform.
ncn-s00(1/2/3)# ceph orch ps
Example output:
NAME HOST STATUS REFRESHED AGE VERSION IMAGE NAME IMAGE ID CONTAINER ID
mds.cephfs.ncn-s001.zwptsg ncn-s001 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c bb08bcb2f034
mds.cephfs.ncn-s002.qyvoyv ncn-s002 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 32c3ff10be42
mds.cephfs.ncn-s003.vvsuvy ncn-s003 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c e172b979c747
mgr.ncn-s001 ncn-s001 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c ad887936d37f
mgr.ncn-s002 ncn-s002 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 80902ae9010c
mgr.ncn-s003 ncn-s003 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 28700bb4053e
mon.ncn-s001 ncn-s001 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c af8d64f9df8a
mon.ncn-s002 ncn-s002 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 698557732bf4
mon.ncn-s003 ncn-s003 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 27421ddd81bd
osd.0 ncn-s003 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 97f4f922edc7
osd.1 ncn-s002 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 69d11a7ddecb
osd.10 ncn-s002 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c aa054d15d4ab
osd.11 ncn-s001 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c b3814f3348ed
osd.2 ncn-s001 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 998c334e41c6
osd.3 ncn-s002 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c da2daa780fd0
osd.4 ncn-s003 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c b831003fdf32
osd.5 ncn-s001 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 6850b49c9bc1
osd.6 ncn-s003 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 6aeb8b274212
osd.7 ncn-s002 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 4eb2f577daba
osd.8 ncn-s001 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c f0386c093874
osd.9 ncn-s003 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 50d7066f66a6
rgw.site1.zone1.ncn-s001.xtjggh ncn-s001 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 6a90ba6415e6
rgw.site1.zone1.ncn-s002.divvfs ncn-s002 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c 825c5b5f33c5
rgw.site1.zone1.ncn-s003.spojqa ncn-s003 running (3d) 7m ago 3d 15.2.8 registry.local/ceph/ceph:v15.2.8 5553b0cb212c f95116a16e41
IMPORTANT: All of the below ceph orch commands should be run from ncn-s001/2/3 or ncn-m001/2/3.
Start the ceph-mon service:
NOTEThe mon process can have a container ID appended to the end of the host name. Please use the output from above to ensure the correct name is used.
ncn-s00(1/2/3)# ceph orch daemon start mon.<hostname>
Stop the ceph-mon service:
ncn-s00(1/2/3)# ceph orch daemon stop mon.<hostname>
Restart the ceph-mon service:
ncn-s00(1/2/3)# ceph orch daemon restart mon.<hostname>
Start the ceph-osd service:
ncn-s00(1/2/3)# ceph orch daemon start osd.<number>
Stop the ceph-osd service:
nncn-s00(1/2/3)# ceph orch daemon stop osd.<number>
Restart the ceph-osd service:
ncn-s00(1/2/3)# ceph orch daemon restart osd.<number>
Start the ceph-mgr service:
ncn-s00(1/2/3)# ceph orch daemon start mgr.<hostname>
Stop the ceph-mgr service:
ncn-s00(1/2/3)# ceph orch daemon stop mgr.<hostname>
Restart the ceph-mgr service:
ncn-s00(1/2/3)# ceph orch daemon restart mgr.<hostname>
Start the ceph-mgr service:
ncn-s00(1/2/3)# ceph orch daemon start mds.cephfs.<container id from ceph orch ps output>
Stop the ceph-mgr service:
ncn-s00(1/2/3)# ceph orch daemon stop mds.cephfs.<container id from ceph orch ps output>
Restart the ceph-mgr service:
ncn-s00(1/2/3)# ceph orch daemon restart mds.cephfs.<container id from ceph orch ps output>
Start the rados-gateway:
ncn-s00(1/2/3)# ceph orch daemon start rgw.site1.zone1.<container id from ceph orch ls>
Stop the rados-gateway:
ncn-s00(1/2/3)# ceph orch daemon stop rgw.site1.zone1.<container id from ceph orch ls>
Restart the rados-gateway:
ncn-s00(1/2/3)# ceph orch daemon restart rgw.site1.zone1.<container id from ceph orch ls>
IMPORTANT: The following commands need to run from the host where services are being started or stopped.
Get the service system_unit:
cephadm ls
Example output:
{
"style": "cephadm:v1",
"name": "mgr.ncn-s001",
"fsid": "01a0d9d2-ea7f-43dc-af25-acdfa5242a48",
"systemd_unit": "ceph-01a0d9d2-ea7f-43dc-af25-acdfa5242a48@mgr.ncn-s001",
"enabled": false,
"state": "running",
"container_id": "ad887936d37fd87999b140c366ef288443faf03e869219bdd282b5825be14d6e",
"container_image_name": "registry.local/ceph/ceph:v15.2.8",
"container_image_id": "5553b0cb212ca2aa220d33ba39d9c602c8412ce6c5febc57ef9cdc9c5844b185",
"version": "15.2.8",
"started": "2021-06-17T22:41:45.132838Z",
"created": "2021-06-17T22:17:51.063202Z",
"deployed": "2021-06-17T22:16:03.898845Z",
"configured": "2021-06-17T22:41:07.807004Z"
},
Restart the service:
systemctl restart ceph-01a0d9d2-ea7f-43dc-af25-acdfa5242a48@mgr.ncn-s001
Location: Ceph manager modules can be enabled or disabled from any ceph-mon nodes.
Enable Ceph manager modules:
ceph mgr MODULE_NAME enable MODULE
Disable Ceph manager modules:
ceph mgr MODULE_NAME disable MODULE
Ceph has the ability to deploy/scale/reconfigure/redeploy Ceph processes down and back up to restart the services.
IMPORTANT: When scaling the Ceph manager daemon (mgr.hostname.
), keep in mind that there must be a running manager daemon as it is what is controlling the orchestration processes.
IMPORTANT: osd.all-available-devices cannot be scaled; this is the process to auto-discover available OSDs.
IMPORTANT: The crash service cannot be scaled; this is the equivalent of a Kubernetes daemon set and runs on all nodes to collect crash data.
The following example shows scaling the mgr service down and back up.
Two SSH sessions are required. One to do the work from and another that is running watch ceph -s to monitor the progress.
List the services.
ceph orch ls
Example output:
NAME RUNNING REFRESHED AGE PLACEMENT IMAGE NAME IMAGE ID
crash 6/6 9s ago 4d * registry.local/ceph/ceph:v15.2.8 5553b0cb212c
mds.cephfs 3/3 9s ago 4d ncn-s001;ncn-s002;ncn-s003;count:3 registry.local/ceph/ceph:v15.2.8 5553b0cb212c
mgr 3/3 9s ago 4d ncn-s001;ncn-s002;ncn-s003;count:3 registry.local/ceph/ceph:v15.2.8 5553b0cb212c
mon 3/3 9s ago 4d ncn-s001;ncn-s002;ncn-s003;count:3 registry.local/ceph/ceph:v15.2.8 5553b0cb212c
osd.all-available-devices 6/6 9s ago 4d * registry.local/ceph/ceph:v15.2.8 5553b0cb212c
rgw.site1.zone1 3/3 9s ago 4d ncn-s001;ncn-s002;ncn-s003;ncn-s004;ncn-s005;ncn-s006;count:3 registry.local/ceph/ceph:v15.2.8 5553b0cb212c
(Optional) Limit the results.
Syntax: ceph orch [<service_type>] [<service_name>] [--export] [plain|json|json-pretty|yaml] [--refresh]
ceph orch ls mgr
Example output:
NAME RUNNING REFRESHED AGE PLACEMENT IMAGE NAME IMAGE ID
mgr 3/3 17s ago 4d ncn-s001;ncn-s002;ncn-s003;count:3 registry.local/ceph/ceph:v15.2.8 5553b0cb212c
The placement of the services is retrieved with this command.
Choose the service to scale. (reminder the example will use the MGR service)
If scaling mds or mgr daemons, make sure to fail over the active mgr/mds daemon so there is always one running.
# To get the active MDS
ceph fs status -f json-pretty|jq -r '.mdsmap[]|select(.state=="active")|.name'
cephfs.ncn-s001.juehkw <-- current active MDS. note this will change when you fail it over so keep this command handy
# To get the active MGR
ceph mgr dump | jq -r .active_name
ncn-s002.fumzfm <-- current active MGR. note this will change when you fail it over so keep this command handy
Now, the service, current placement policy, and if applicable, the active MGR/MDS daemon are all known.
Scale the service.
ceph orch apply --placement="1 <host where the active mgr is running>"
For example:
ceph orch apply mgr --placement="1 ncn-s002"
Scheduled mgr update...
Watch the SSH session that is showing the Ceph status (ceph -s).
ceph -s
Example output:
cluster:
id: 11d5d552-cfac-11eb-ab69-fa163ec012bf
health: HEALTH_OK
services:
mon: 3 daemons, quorum ncn-s001,ncn-s002,ncn-s003 (age 70s)
mgr: ncn-s002.fumzfm(active, since 14s)
mds: cephfs:1 {0=cephfs.ncn-s001.juehkw=up:active} 1 up:standby-replay 1 up:standby
osd: 6 osds: 6 up (since 4d), 6 in (since 4d)
rgw: 2 daemons active (site1.zone1.ncn-s005.hzfbkd, site1.zone1.ncn-s006.vjuwkf)
task status:
data:
pools: 7 pools, 193 pgs
objects: 256 objects, 7.5 MiB
usage: 9.1 GiB used, 261 GiB / 270 GiB avail
pgs: 193 active+clean
io:
client: 663 B/s rd, 1 op/s rd, 0 op/s wr
The mgr service is now showing 1 active on the node we chose.
Scale the service back up to 3 mgrs.
ceph orch apply mgr --placement="3 ncn-s001 ncn-s002 ncn-s003"
The returned output will be “Scheduled mgr update…”.
When the Ceph status output shows there are 3 running mgr daemons, scale the last daemon back down and up.
If it is the MDS or MGR daemons, then REMEMBER we have to fail over the active daemon.
ceph mgr fail ncn-s002.fumzfm # This was our active MGR.
In the Ceph status output, the will be an ACTIVE ceph mgr process change.
mgr: ncn-s003.wtvbtz(active, since 2m), standbys: ncn-s001.cgbxdw
Scale the service back to its original deployment size.
ceph orch apply mgr --placement="3 ncn-s001 ncn-s002 ncn-s003"
The returned output will be “Scheduled mgr update…”.
Monitor the Ceph status to make sure all the daemons come back online.