doc/cephadm/services/index.rst
A service is a group of daemons configured together. See these chapters for details on individual services:
.. toctree:: :maxdepth: 1
mon
mgr
osd
rgw
mds
nfs
iscsi
custom-container
monitoring
snmp-gateway
tracing
smb
mgmt-gateway
oauth2-proxy
To see the status of one of the services running in the Ceph cluster, do the following:
#. Use the command line to print a list of services. #. Locate the service whose status you want to check. #. Print the status of the service.
The following command prints a list of services known to the orchestrator. To
limit the output to services only on a specified host, use the optional
--host parameter. To limit the output to services of only a particular
type, use the optional --type parameter
(mon, osd, mgr, mds, rgw):
.. prompt:: bash #
ceph orch ls [--service_type type] [--service_name name] [--export] [--format f] [--refresh]
Discover the status of a particular service or daemon:
.. prompt:: bash #
ceph orch ls --service_type type --service_name <name> [--refresh]
To export the service specifications known to the orchestrator, run the following command:
.. prompt:: bash #
ceph orch ls --export
The service specifications exported with this command will be exported as YAML
and that YAML can be used with the ceph orch apply -i command.
For information about retrieving the specifications of single services
(including examples of commands), see :ref:orchestrator-cli-service-spec-retrieve.
A daemon is a systemd unit that is running and part of a service.
To see the status of a daemon, do the following:
#. Print a list of all daemons known to the orchestrator. #. Query the status of the target daemon.
First, print a list of all daemons known to the orchestrator:
.. prompt:: bash #
ceph orch ps [--hostname host] [--daemon_type type] [--service_name name] [--daemon_id id] [--format f] [--refresh]
Then query the status of a particular service instance (mon, osd, mds, rgw).
For OSDs the id is the numeric OSD ID. For MDS services the id is the file
system name:
.. prompt:: bash #
ceph orch ps --daemon_type osd --daemon_id 0
.. note::
The output of the command ceph orch ps may not reflect the current
status of the daemons. By default, the status is updated every 10 minutes.
This interval can be shortened by modifying the :confval:mgr/cephadm/daemon_cache_timeout
configuration variable (in seconds) e.g: ceph config set mgr mgr/cephadm/daemon_cache_timeout 60 would reduce the refresh interval to
one minute. The --refresh option can be used to trigger
a request to refresh the information, which may take some time depending on
the size of the cluster. In general REFRESHED value indicates how recent
the information displayed by ceph orch ps and similar commands is.
.. _orchestrator-cli-service-spec:
A service specification is a data structure that is used to specify the
deployment of services. In addition to parameters such as placement or
networks, the user can set initial values of service configuration parameters
by means of the config section. For each parameter/value configuration pair,
cephadm calls the following command to set its value:
.. prompt:: bash #
ceph config set <service-name> <param> <value>
Cephadm raises health warnings in case invalid configuration parameters are
found in the spec (CEPHADM_INVALID_CONFIG_OPTION) or if an error occurs while
trying to apply the new configuration option(s) (CEPHADM_FAILED_SET_OPTION).
Here is an example of a service specification in YAML:
.. code-block:: yaml
service_type: rgw
service_id: realm.zone
placement:
hosts:
- host1
- host2
- host3
config:
param_1: val_1
...
param_N: val_N
unmanaged: false
networks:
- 192.169.142.0/24
spec:
# Additional service-specific attributes.
In this example, the properties of this service specification are:
.. py:currentmodule:: ceph.deployment.service_spec
.. autoclass:: ServiceSpec :members:
Each service type can have additional service-specific properties.
Service specifications of type mon, mgr, and the monitoring
types do not require a service_id.
A service of type osd is described in :ref:drivegroups.
Many service specifications can be applied at once using ceph orch apply -i
by submitting a multi-document YAML file:
.. prompt:: bash # auto
# cat <<EOF | ceph orch apply -i -
service_type: mon
placement:
host_pattern: "mon*"
---
service_type: mgr
placement:
host_pattern: "mgr*"
---
service_type: osd
service_id: default_drive_group
placement:
host_pattern: "osd*"
data_devices:
all: true
EOF
.. _orchestrator-cli-service-spec-retrieve:
If the services have been started via ceph orch apply ..., then directly changing
the service specification is complicated. Instead of attempting to directly change
the service specification, we suggest exporting the running service specification by
following these instructions:
.. prompt:: bash #
ceph orch ls --service-name rgw.<realm>.<zone> --export > rgw.<realm>.<zone>.yaml
ceph orch ls --service-type mgr --export > mgr.yaml
ceph orch ls --export > cluster.yaml
The specification can then be changed and re-applied as above.
The Ceph orchestrator maintains a declarative state of each
service in a ServiceSpec. For certain operations, like updating
the RGW HTTP port, we need to update the existing
specification.
#. List the current ServiceSpec:
.. prompt:: bash #
ceph orch ls --service_name=<service-name> --export > myservice.yaml
#. Update the YAML file:
.. prompt:: bash #
vi myservice.yaml
#. Apply the new ServiceSpec:
.. prompt:: bash #
ceph orch apply -i myservice.yaml [--dry-run]
.. _orchestrator-cli-placement-spec:
For the orchestrator to deploy a service, it needs to know where to deploy daemons, and how many to deploy. This is the role of a placement specification. Placement specifications can either be passed as command line arguments or in a YAML files.
.. note::
Cephadm will not deploy daemons on hosts with the _no_schedule label;
see :ref:cephadm-special-host-labels.
.. note::
The apply command can be confusing. For this reason, we recommend using
YAML specifications.
Each ceph orch apply <service-name> command supersedes the one before it.
If you do not use the proper syntax, you will clobber your work
as you go.
For example:
.. prompt:: bash #
ceph orch apply mon host1
ceph orch apply mon host2
ceph orch apply mon host3
This results in only one host having a monitor applied to it: host3.
(The first command creates a monitor on host1. Then the second command
clobbers the monitor on host1 and creates a monitor on host2. Then the
third command clobbers the monitor on host2 and creates a monitor
on host3. In this scenario, at this point, there is a monitor only
on host3.)
To make certain that a monitor is applied to each of these three hosts, run a command like this:
.. prompt:: bash #
ceph orch apply mon "host1,host2,host3"
There is another way to apply monitors to multiple hosts: a YAML file
can be used. Instead of using the ceph orch apply mon commands, run a
command of this form:
.. prompt:: bash #
ceph orch apply -i file.yaml
Here is a sample file.yaml file:
.. code-block:: yaml
service_type: mon
placement:
hosts:
- host1
- host2
- host3
Daemons can be explicitly placed on hosts by simply specifying them:
.. prompt:: bash #
ceph orch apply prometheus --placement="host1 host2 host3"
Or in YAML:
.. code-block:: yaml
service_type: prometheus
placement:
hosts:
- host1
- host2
- host3
Monitors and other services may require some enhanced network specifications:
.. prompt:: bash #
ceph orch daemon add mon --placement="myhost:[v2:1.2.3.4:3300,v1:1.2.3.4:6789]=name"
where [v2:1.2.3.4:3300,v1:1.2.3.4:6789] is the network address of the monitor
and =name specifies the name of the new monitor.
.. _orch-placement-by-labels:
Daemon placement can be limited to hosts that match a specific label. To set
a label mylabel to the appropriate hosts, run this command:
.. prompt:: bash #
ceph orch host label add <hostname> mylabel
To view the current hosts and labels, run this command:
.. prompt:: bash #
ceph orch host ls
For example:
.. prompt:: bash #
ceph orch host label add host1 mylabel
ceph orch host label add host2 mylabel
ceph orch host label add host3 mylabel
ceph orch host ls
.. code-block:: bash
HOST ADDR LABELS STATUS
host1 mylabel
host2 mylabel
host3 mylabel
host4
host5
Now, tell cephadm to deploy daemons based on the label by running this command:
.. prompt:: bash #
ceph orch apply prometheus --placement="label:mylabel"
Or in YAML:
.. code-block:: yaml
service_type: prometheus
placement:
label: "mylabel"
See :ref:orchestrator-host-labels for more information.
.. _cephadm-services-placement-by-pattern-matching:
Daemons can be placed on hosts using a host pattern as well. By default, the host pattern is matched using fnmatch which supports UNIX shell-style wildcards (see https://docs.python.org/3/library/fnmatch.html):
.. prompt:: bash #
ceph orch apply prometheus --placement='myhost[1-3]'
Or in YAML:
.. code-block:: yaml
service_type: prometheus
placement:
host_pattern: "myhost[1-3]"
To place a service on all hosts, use "*":
.. prompt:: bash #
ceph orch apply node-exporter --placement='*'
Or in YAML:
.. code-block:: yaml
service_type: node-exporter
placement:
host_pattern: "*"
The host pattern also has support for using a regular expression. To use a regex, you
must either add "regex:" to the start of the pattern when using the
command line, or specify a pattern_type field to be regex
when using YAML.
On the command line:
.. prompt:: bash #
ceph orch apply prometheus --placement='regex:FOO[0-9]|BAR[0-9]'
In YAML:
.. code-block:: yaml
service_type: prometheus
placement:
host_pattern:
pattern: 'FOO[0-9]|BAR[0-9]'
pattern_type: regex
By specifying count, only the number of daemons specified will be created:
.. prompt:: bash #
ceph orch apply prometheus --placement=3
To deploy daemons on a subset of hosts, specify the count and host names or
:ref:patterns <cephadm-services-placement-by-pattern-matching> for the subset:
.. prompt:: bash #
ceph orch apply prometheus --placement="2 host1 host2 host3"
If the count is bigger than the amount of hosts, cephadm deploys one per host:
.. prompt:: bash #
ceph orch apply prometheus --placement="3 host1 host2"
The command immediately above results in two Prometheus daemons.
YAML can also be used to specify limits, in the following way:
.. code-block:: yaml
service_type: prometheus
placement:
count: 3
YAML can also be used to specify limits on hosts:
.. code-block:: yaml
service_type: prometheus
placement:
count: 2
hosts:
- host1
- host2
- host3
.. _cephadm_co_location:
Cephadm supports the deployment of multiple daemons on the same host:
.. code-block:: yaml
service_type: rgw
placement:
label: rgw
count_per_host: 2
The main reason for deploying multiple daemons per host is an additional performance benefit for running multiple RGW and MDS daemons on the same host.
See also:
cephadm_mgr_co_location.cephadm-rgw-designated_gateways.This feature was introduced in Pacific.
Cephadm's declarative state consists of a list of service specifications containing placement specifications.
Cephadm continually compares a list of daemons actually running in the cluster against the list in the service specifications. Cephadm adds new daemons and removes old daemons as necessary in order to conform to the service specifications.
Cephadm does the following to maintain compliance with the service specifications.
Cephadm first selects a list of candidate hosts. Cephadm seeks explicit host names and selects them. If cephadm finds no explicit host names, it looks for label specifications. If no label is defined in the specification, cephadm selects hosts based on a host pattern. If no host pattern is defined, as a last resort, cephadm selects all known hosts as candidates.
Cephadm is aware of existing daemons running services and tries to avoid moving them.
Cephadm supports the deployment of a specific amount of services. Consider the following service specification:
.. code-block:: yaml
service_type: mds
service_name: myfs
placement:
count: 3
label: myfs
This service specification instructs cephadm to deploy three daemons on hosts
labeled myfs across the cluster.
If there are fewer than three daemons deployed on the candidate hosts, cephadm randomly chooses hosts on which to deploy new daemons.
If there are more than three daemons deployed on the candidate hosts, cephadm removes existing daemons.
Finally, cephadm removes daemons on hosts that are outside of the list of candidate hosts.
.. note::
There is a special case that cephadm must consider.
If there are fewer hosts selected by the placement specification than
demanded by count, cephadm will deploy only on the selected hosts.
.. _cephadm-extra-container-args:
.. warning::
The arguments provided for extra container args are limited to whatever arguments are available for
a run command from whichever container engine you are using. Providing any arguments the run
command does not support (or invalid values for arguments) will cause the daemon to fail to start.
.. note::
For arguments passed to the process running inside the container rather than the for
the container runtime itself, see :ref:cephadm-extra-entrypoint-args.
Cephadm supports providing extra miscellaneous container arguments for specific cases when they may be necessary. For example, if a user needed to limit the amount of CPUs their Monitor daemons make use of they could apply a spec like:
.. code-block:: yaml
service_type: mon
service_name: mon
placement:
hosts:
- host1
- host2
- host3
extra_container_args:
- "--cpus=2"
which would cause each Monitor daemon to be deployed with --cpus=2.
There are two ways to express arguments in the extra_container_args list.
To start, an item in the list can be a string. When passing an argument
as a string and the string contains spaces, cephadm will automatically split it
into multiple arguments. For example, --cpus 2 would become ["--cpus", "2"] when processed. Example:
.. code-block:: yaml
service_type: mon
service_name: mon
placement:
hosts:
- host1
- host2
- host3
extra_container_args:
- "--cpus 2"
As an alternative, an item in the list can be an object (mapping) containing
the required key argument and an optional key split. The value associated
with the argument key must be a single string. The value associated with
the split key is a boolean value. The split key explicitly controls if
spaces in the argument value cause the value to be split into multiple
arguments. If split is true then cephadm will automatically split the value
into multiple arguments. If split is false then spaces in the value will
be retained in the argument. The default, when split is not provided, is
false. Examples:
.. code-block:: yaml
service_type: mon
service_name: mon
placement:
hosts:
- tiebreaker
extra_container_args:
# No spaces, always treated as a single argument
- argument: "--timout=3000"
# Splitting explicitly disabled, one single argument
- argument: "--annotation=com.example.name=my favorite mon"
split: false
# Splitting explicitly enabled, will become two arguments
- argument: "--cpuset-cpus 1-3,7-11"
split: true
# Splitting implicitly disabled, one single argument
- argument: "--annotation=com.example.note=a simple example"
A common use case for extra container arguments is to mount additional files within the container. Older versions of Ceph did not support spaces in arguments and therefore the examples below apply to the widest range of Ceph versions.
.. code-block:: yaml
extra_container_args:
- "-v"
- "/absolute/file/path/on/host:/absolute/file/path/in/container"
For example:
.. code-block:: yaml
extra_container_args:
- "-v"
- "/opt/ceph_cert/host.cert:/etc/grafana/certs/cert_file:ro"
.. _cephadm-extra-entrypoint-args:
.. note::
For arguments intended for the container runtime rather than the process inside
it, see :ref:cephadm-extra-container-args.
Similar to extra container args for the container runtime, cephadm supports
appending to args passed to the entrypoint process running
within a container. For example, to set the collector textfile directory for
the node-exporter service, one could apply a service spec like:
.. code-block:: yaml
service_type: node-exporter
service_name: node-exporter
placement:
host_pattern: '*'
extra_entrypoint_args:
- "--collector.textfile.directory=/var/lib/node_exporter/textfile_collector2"
There are two ways to express arguments in the extra_entrypoint_args list.
To start, an item in the list can be a string. When passing an argument as a
string and the string contains spaces, cephadm will automatically split it into
multiple arguments. For example, --debug_ms 10 would become
["--debug_ms", "10"] when processed. Example:
.. code-block:: yaml
service_type: mon
service_name: mon
placement:
hosts:
- host1
- host2
- host3
extra_entrypoint_args:
- "--debug_ms 2"
As an alternative, an item in the list can be an object (mapping) containing
the required key argument and an optional key split. The value associated
with the argument key must be a single string. The value associated with
the split key is a boolean value. The split key explicitly controls if
spaces in the argument value cause the value to be split into multiple
arguments. If split is true then cephadm will automatically split the value
into multiple arguments. If split is false then spaces in the value will
be retained in the argument. The default, when split is not provided, is
false. Examples:
.. code-block:: yaml
# A theoretical data migration service
service_type: pretend
service_name: imagine1
placement:
hosts:
- host1
extra_entrypoint_args:
# No spaces, always treated as a single argument
- argument: "--timout=30m"
# Splitting explicitly disabled, one single argument
- argument: "--import=/mnt/usb/My Documents"
split: false
# Splitting explicitly enabled, will become two arguments
- argument: "--tag documents"
split: true
# Splitting implicitly disabled, one single argument
- argument: "--title=Imported Documents"
Cephadm supports specifying miscellaneous config files for daemons. To do so, users must provide both the content of the config file and the location within the daemon's container at which it should be mounted. After applying a YAML spec with custom config files specified and having cephadm redeploy the daemons for which the config files are specified, these files will be mounted within the daemon's container at the specified location.
Example service spec:
.. code-block:: yaml
service_type: grafana
service_name: grafana
custom_configs:
- mount_path: /etc/example.conf
content: |
setting1 = value1
setting2 = value2
- mount_path: /usr/share/grafana/example.cert
content: |
-----BEGIN PRIVATE KEY-----
V2VyIGRhcyBsaWVzdCBpc3QgZG9vZi4gTG9yZW0gaXBzdW0gZG9sb3Igc2l0IGFt
ZXQsIGNvbnNldGV0dXIgc2FkaXBzY2luZyBlbGl0ciwgc2VkIGRpYW0gbm9udW15
IGVpcm1vZCB0ZW1wb3IgaW52aWR1bnQgdXQgbGFib3JlIGV0IGRvbG9yZSBtYWdu
YSBhbGlxdXlhbSBlcmF0LCBzZWQgZGlhbSB2b2x1cHR1YS4gQXQgdmVybyBlb3Mg
ZXQgYWNjdXNhbSBldCBqdXN0byBkdW8=
-----END PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
V2VyIGRhcyBsaWVzdCBpc3QgZG9vZi4gTG9yZW0gaXBzdW0gZG9sb3Igc2l0IGFt
ZXQsIGNvbnNldGV0dXIgc2FkaXBzY2luZyBlbGl0ciwgc2VkIGRpYW0gbm9udW15
IGVpcm1vZCB0ZW1wb3IgaW52aWR1bnQgdXQgbGFib3JlIGV0IGRvbG9yZSBtYWdu
YSBhbGlxdXlhbSBlcmF0LCBzZWQgZGlhbSB2b2x1cHR1YS4gQXQgdmVybyBlb3Mg
ZXQgYWNjdXNhbSBldCBqdXN0byBkdW8=
-----END CERTIFICATE-----
To make these new config files actually get mounted within the containers for the daemons, run a command of the following form:
.. prompt:: bash #
ceph orch redeploy <service-name>
For example:
.. prompt:: bash #
ceph orch redeploy grafana
.. _orch-rm:
In order to remove a service including the removal of all daemons of that service, run a command of the following form:
.. prompt:: bash #
ceph orch rm <service-name>
For example:
.. prompt:: bash #
ceph orch rm rgw.myrgw
.. _cephadm-spec-unmanaged:
Cephadm supports disabling the automated deployment and removal of daemons on a per-service basis. The CLI supports two commands for this.
In order to fully remove a service, see :ref:orch-rm.
To disable the automatic management of daemons, set unmanaged=True in the
:ref:orchestrator-cli-service-spec (mgr.yaml).
mgr.yaml:
.. code-block:: yaml
service_type: mgr
unmanaged: true
placement:
label: mgr
.. prompt:: bash #
ceph orch apply -i mgr.yaml
Cephadm also supports setting the unmanaged parameter to true or false
using the ceph orch set-unmanaged and ceph orch set-managed commands.
The commands take the service name (as reported in ceph orch ls) as
the only argument. For example,
.. prompt:: bash #
ceph orch set-unmanaged mon
would set unmanaged: true for the mon service and
.. prompt:: bash #
ceph orch set-managed mon
would set unmanaged: false for the mon service.
.. note::
After you apply this change in the service specification, cephadm will no longer deploy any new daemons (even if the placement specification matches additional hosts).
.. note::
The osd service used to track OSDs that are not tied to any specific
service spec is special and will always be marked unmanaged. Attempting
to modify it with ceph orch set-unmanaged or ceph orch set-managed
will result in a message No service of name osd found. Check "ceph orch ls" for all known services.
.. note::
This workflow has a very limited use case and should only be used in rare circumstances.
To manually deploy a daemon on a host, follow these steps:
Modify the service spec for a service by getting the
existing spec, adding unmanaged: true, and applying the modified spec.
Then manually deploy the daemon by running a command of the following form:
.. prompt:: bash #
ceph orch daemon add <daemon-type> --placement=<placement spec>
For example :
.. prompt:: bash #
ceph orch daemon add mgr --placement=my_host
.. note::
Removing unmanaged: true from the service spec will
enable the reconciliation loop for this service and will
potentially lead to the removal of the daemon, depending
on the placement spec.
To manually remove a daemon, run a command of the following form:
.. prompt:: bash #
ceph orch daemon rm <daemon name>... [--force]
For example:
.. prompt:: bash #
ceph orch daemon rm mgr.my_host.xyzxyz
.. note::
For managed services (unmanaged=False), cephadm will automatically
deploy a new daemon a few seconds later.
cephadm-osd-declarative for special handling of unmanaged OSDs.cephadm-pause.