doc/cephadm/operations.rst
.. _watching_cephadm_logs:
The cephadm orchestrator module writes logs to the cephadm cluster log
channel. You can monitor Ceph's activity in real time by reading the logs as
they fill up. Run the following command to see the logs in real time:
.. prompt:: bash #
ceph -W cephadm
By default, this command shows info-level events and above. To see debug-level messages as well as info-level events, run the following commands:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/log_to_cluster_level debug ceph -W cephadm --watch-debug
.. warning::
The debug messages are very verbose!
You can see recent events by running the following command:
.. prompt:: bash #
ceph log last cephadm
These events are also logged to the ceph.cephadm.log file on
monitor hosts as well as to the Monitor daemons' stderr.
You can stop, start, or restart a daemon with:
.. prompt:: bash #
ceph orch daemon stop <daemonid> ceph orch daemon start <daemonid> ceph orch daemon restart <daemonid>
You can also do the same for all daemons for a service with:
.. prompt:: bash #
ceph orch stop <serviceid> ceph orch start <serviceid> ceph orch restart <serviceid>
.. note::
It is usually not safe to run ceph orch restart osd.myosdservice on a
running cluster, as attention is not paid to CRUSH failure domains, and
parallel OSD restarts may lead to temporary data unavailability or in rare
cases even data loss.
The container for a daemon can be stopped, recreated, and restarted with
the redeploy command:
.. prompt:: bash #
ceph orch daemon redeploy <name> [--image <image>]
A container image name can optionally be provided to force a
particular image to be used (instead of the image specified by the
container_image config value).
If only the Ceph configuration needs to be regenerated, you can also
issue a reconfig command, which will rewrite the ceph.conf
file but will not trigger a restart of the daemon.
.. prompt:: bash #
ceph orch daemon reconfig <name>
All Ceph and gateway daemons in the cluster have a secret key that is used to connect to and authenticate with the cluster. This key can be rotated (i.e., replaced with a new key) with the following command:
.. prompt:: bash #
ceph orch daemon rotate-key <name>
For MDS, OSD, and Manager daemons, this does not require a daemon restart. For other daemons, however (e.g., RGW), the daemon may be restarted to switch to the new key.
.. _cephadm-logs:
Ceph daemons traditionally write logs to /var/log/ceph. Ceph daemons log to
journald by default and Ceph logs are captured by the container runtime
environment. They are accessible via journalctl.
.. note:: Prior to Quincy, Ceph daemons logged to stderr.
Example of Logging to Journald
For example, to view the logs for the daemon ``mon.foo`` for a cluster
with ID ``5c5a50ae-272a-455d-99e9-32c6a013e694``, the command would be
something like:
.. prompt:: bash #
journalctl -u [email protected]
This works well for normal operations when logging levels are low.
Logging to Files
----------------
You can also configure Ceph daemons to log to files instead of
journald if you prefer logs to appear in files (as they did in earlier,
pre-cephadm, pre-Octopus versions of Ceph). When Ceph logs to files,
the logs appear in ``/var/log/ceph/<cluster-fsid>``. If you choose to
configure Ceph to log to files instead of journald, remember to
configure Ceph so that it will not log to journald (the commands for
this are covered below).
Enabling Logging to Files
~~~~~~~~~~~~~~~~~~~~~~~~~
To enable logging to files, run the following commands:
.. prompt:: bash #
ceph config set global log_to_file true
ceph config set global mon_cluster_log_to_file true
Disabling Logging to Journald
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If you choose to log to files, we recommend disabling logging to journald or else
everything will be logged twice. Run the following commands to disable logging
to stderr:
.. prompt:: bash #
ceph config set global log_to_stderr false
ceph config set global mon_cluster_log_to_stderr false
ceph config set global log_to_journald false
ceph config set global mon_cluster_log_to_journald false
.. note:: You can change the default by passing ``--log-to-file`` during
bootstrapping a new cluster.
Modifying the Log Retention Schedule
By default, cephadm sets up log rotation on each host to rotate these
files. You can configure the logging retention schedule by modifying
/etc/logrotate.d/ceph.<cluster-fsid>.
The cephadm executable, either run directly by a user or by the cephadm
orchestration module, may also generate logs. It does so independently of
the other Ceph components running in containers. By default, this executable
logs to the file /var/log/ceph/cephadm.log.
This logging destination is configurable and you may choose to log to the file, to the syslog/journal, or to both.
The cephadm command may be executed with the option --log-dest=file
or with --log-dest=syslog or both. These options control where cephadm
will store persistent logs for each invocation. When these options are
specified for the cephadm bootstrap command the system will automatically
record these settings for future invocations of cephadm by the cephadm
orchestration module.
For example:
.. prompt:: bash #
cephadm --log-dest=syslog bootstrap # ... other bootstrap arguments ...
If you want to manually specify exactly what log destination to use
during bootstrap, independent from the --log-dest options, you may add
a configuration key :confval:mgr/cephadm/cephadm_log_destination to the
initial configuration file, under the [mgr] section. Valid values for
the key are: file, syslog, and file,syslog.
For example:
.. prompt:: bash # auto
[mgr] mgr/cephadm/cephadm_log_destination = syslog EOF
An existing Ceph cluster can be configured to use a specific cephadm log
destination by setting the :confval:mgr/cephadm/cephadm_log_destination
configuration value to one of file, syslog, or file,syslog. This
will cause the cephadm orchestration module to run cephadm so that logs go
to /var/log/ceph/cephadm.log, the syslog/journal, or both, respectively.
For example:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/cephadm_log_destination syslog
ceph config set mgr mgr/cephadm/cephadm_log_destination file,syslog
ceph config set mgr mgr/cephadm/cephadm_log_destination file
.. note:: If you execute cephadm commands directly, such as cephadm shell,
this option will not apply. To have cephadm log to locations other than
the default log file when running cephadm commands directly use the
--log-dest options described in the bootstrap section above.
Cephadm stores daemon data and logs in different locations than did older, pre-cephadm (pre-Octopus) versions of Ceph:
/var/log/ceph/<cluster-fsid> contains all cluster logs. By
default, cephadm logs via stderr and the container runtime. These
logs will not exist unless you have enabled logging to files as
described in :ref:cephadm-logs./var/lib/ceph/<cluster-fsid> contains all cluster daemon data
(besides logs)./var/lib/ceph/<cluster-fsid>/<daemon-name> contains all data for
an individual daemon./var/lib/ceph/<cluster-fsid>/crash contains crash reports for
the cluster./var/lib/ceph/<cluster-fsid>/removed contains old daemon
data directories for stateful daemons (e.g., Monitor, Prometheus)
that have been removed by cephadm.Because a few Ceph daemons (notably, the Monitors and Prometheus) store a
large amount of data in /var/lib/ceph , we recommend moving this
directory to its own disk, partition, or logical volume so that it does not
fill up the root file system.
The cephadm module provides additional health checks to supplement the default health checks provided by the cluster. These additional health checks fall into two categories:
CEPHADM_PAUSED
This indicates that cephadm background work has been paused with
``ceph orch pause``. Cephadm continues to perform passive monitoring
activities (like checking host and daemon status), but it will not
make any changes (like deploying or removing daemons).
Resume cephadm work by running the following command:
.. prompt:: bash #
ceph orch resume
.. _cephadm-stray-host:
``CEPHADM_STRAY_HOST``
This indicates that one or more hosts have Ceph daemons that are
running, but are not registered as hosts managed by cephadm. This
means that those services cannot currently be managed by cephadm
(e.g., restarted, upgraded, included in ceph orch ps).
You can manage the host(s) by running the following command:
.. prompt:: bash #
ceph orch host add <hostname>
.. note::
You might need to configure SSH access to the remote host before this will work.
See :ref:cephadm-adding-hosts for more information.
See :ref:cephadm-fqdn for more information about host names and
domain names.
Alternatively, you can manually connect to the host and ensure that services on that host are removed or migrated to a host that is managed by cephadm.
This warning can be disabled entirely by running the following command:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/warn_on_stray_hosts false
CEPHADM_STRAY_DAEMON
One or more Ceph daemons are running but are not managed by
*cephadm*. This may be because they were deployed using a different
tool, or because they were started manually. Those
services cannot currently be managed by cephadm (e.g., restarted,
upgraded, or included in ``ceph orch ps``).
* If the daemon is a stateful one (Monitor or OSD), it should be adopted
by cephadm; see :ref:`cephadm-adoption`. For stateless daemons, it is
usually easiest to provision a new daemon with the ``ceph orch apply``
command and then stop the unmanaged daemon.
* If the stray daemon(s) are running on hosts not managed by cephadm, you can
manage the host(s) by running the following command:
.. prompt:: bash #
ceph orch host add <hostname>
.. note::
You might need to configure SSH access to the remote host
before this will work.
See :ref:`cephadm-adding-hosts` for more information.
* See :ref:`cephadm-fqdn` for more information about host names and
domain names.
* This warning can be disabled entirely by running the following command:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/warn_on_stray_daemons false
``CEPHADM_HOST_CHECK_FAILED``
One or more hosts have failed the basic cephadm host check, which verifies that (1) the host is reachable and cephadm can be executed there, and (2) that the host satisfies basic prerequisites, like a working container runtime (Podman or Docker) and working time synchronization. If this test fails, cephadm will not be able to manage services on that host.
You can manually run this check by running the following command:
.. prompt:: bash #
ceph cephadm check-host <hostname>
You can remove a broken host from management by running the following command:
.. prompt:: bash #
ceph orch host rm <hostname>
See :ref:cephadm-removing-hosts for more information.
You can disable this health warning by running the following command:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/warn_on_failed_host_check false
Cephadm periodically scans each host in the cluster in order to understand the state of the OS, disks, network interfaces etc. This information can then be analyzed for consistency across the hosts in the cluster to identify any configuration anomalies.
Enabling Cluster Configuration Checks
These configuration checks are an **optional** feature, and are enabled
by running the following command:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/config_checks_enabled true
States Returned by Cluster Configuration Checks
Configuration checks are triggered after each host scan. The cephadm log entries will show the current state and outcome of the configuration checks as follows:
Disabled state (config_checks_enabled set to false):
.. code-block:: console
ALL cephadm checks are disabled, use 'ceph config set mgr mgr/cephadm/config_checks_enabled true' to enable
Enabled state (config_checks_enabled set to true):
.. code-block:: console
CEPHADM 8/8 checks enabled and executed (0 bypassed, 0 disabled). No issues detected
Managing Configuration Checks (Subcommands)
The configuration checks themselves are managed through several cephadm subcommands.
To determine whether the configuration checks are enabled, run the following command:
.. prompt:: bash #
ceph cephadm config-check status
This command returns the status of the configuration checker as either "Enabled" or "Disabled".
To list all the configuration checks and their current states, run the following command:
.. prompt:: bash #
ceph cephadm config-check ls
.. code-block:: console
NAME HEALTHCHECK STATUS DESCRIPTION
kernel_security CEPHADM_CHECK_KERNEL_LSM enabled check that SELINUX/Apparmor profiles are consistent across cluster hosts
os_subscription CEPHADM_CHECK_SUBSCRIPTION enabled check that subscription states are consistent for all cluster hosts
public_network CEPHADM_CHECK_PUBLIC_MEMBERSHIP enabled check that all hosts have a network interface on the Ceph public_network
osd_mtu_size CEPHADM_CHECK_MTU enabled check that OSD hosts share a common MTU setting
osd_linkspeed CEPHADM_CHECK_LINKSPEED enabled check that OSD hosts share a common network link speed
network_missing CEPHADM_CHECK_NETWORK_MISSING enabled check that the cluster/public networks as defined exist on the Ceph hosts
ceph_release CEPHADM_CHECK_CEPH_RELEASE enabled check for Ceph version consistency: all Ceph daemons should be the same release unless upgrade is in progress
kernel_version CEPHADM_CHECK_KERNEL_VERSION enabled checks that the maj.min version of the kernel is consistent across Ceph hosts
The name of each configuration check can be used to enable or disable a specific check by running a command of the following form:
.. prompt:: bash #
ceph cephadm config-check [enable|disable] <name>
For example:
.. prompt:: bash #
ceph cephadm config-check disable kernel_security
``CEPHADM_CHECK_KERNEL_LSM``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Each host within the cluster is expected to operate within the same Linux
Security Module (LSM) state. For example, if the majority of the hosts are
running with SELinux in enforcing mode, any host not running in this mode is
flagged as an anomaly and a health check warning is raised.
``CEPHADM_CHECK_SUBSCRIPTION``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This check relates to the status of OS vendor subscription. This check is
performed only for hosts using RHEL and helps to confirm that all hosts are
covered by an active subscription, which ensures that patches and updates are
available.
``CEPHADM_CHECK_PUBLIC_MEMBERSHIP``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All members of the cluster should have a network interface configured on at least one of the
public network subnets. Hosts that are not on the public network will rely on
routing, which may affect performance.
``CEPHADM_CHECK_MTU``
~~~~~~~~~~~~~~~~~~~~~
The MTU of the network interfaces on OSD hosts can be a key factor in consistent performance. This
check examines hosts that are running OSD services to ensure that the MTU is
configured consistently within the cluster. This is determined by determining
the MTU setting that the majority of hosts is using. Any anomalies result in a
health check warning.
``CEPHADM_CHECK_LINKSPEED``
~~~~~~~~~~~~~~~~~~~~~~~~~~~
This check is similar to the MTU check. Link speed consistency is a factor in
consistent cluster performance, as is the MTU of the OSD node network interfaces.
This check determines the link speed shared by the majority of OSD hosts, and a
health check warning is raised for any hosts that are set at a lower link speed rate.
``CEPHADM_CHECK_NETWORK_MISSING``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The :confval:`public_network` and :confval:`cluster_network` settings support subnet definitions
for IPv4 and IPv6. If these settings are not found on any host in the cluster,
a health check warning is raised.
``CEPHADM_CHECK_CEPH_RELEASE``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Under normal operations, the Ceph cluster runs daemons that are of the same Ceph
release (for example, Reef). This check determines the active release for each daemon, and
reports any anomalies as a health check warning. *This check is bypassed if an upgrade
is in process.*
``CEPHADM_CHECK_KERNEL_VERSION``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The OS kernel version (maj.min) is checked for consistency across hosts.
The kernel version of the majority of the hosts is used as the basis for
identifying anomalies.
.. _client_keyrings_and_configs:
Management of Client Keyrings and Configs
=========================================
Cephadm can distribute copies of the ``ceph.conf`` file and client keyring
files to hosts. Starting from versions 16.2.10 (Pacific) and 17.2.1 (Quincy),
in addition to the default location ``/etc/ceph`` cephadm also stores config
and keyring files in the ``/var/lib/ceph/<fsid>/config`` directory. It is usually
a good idea to store a copy of the config and ``client.admin`` keyring on any host
used to administer the cluster via the CLI. By default, cephadm does this for any
nodes that have the ``_admin`` label (which normally includes the bootstrap host).
.. note:: Ceph daemons will still use files on ``/etc/ceph``. The new configuration
location ``/var/lib/ceph/<fsid>/config`` is used by cephadm only. Having this config
directory under the fsid helps cephadm to load the configuration associated with
the cluster.
When a client keyring is placed under management, cephadm will:
- build a list of target hosts based on the specified placement spec (see
:ref:`orchestrator-cli-placement-spec`)
- store a copy of the ``/etc/ceph/ceph.conf`` file on the specified host(s)
- store a copy of the ``ceph.conf`` file at ``/var/lib/ceph/<fsid>/config/ceph.conf``
on the specified host(s)
- store a copy of the ``ceph.client.admin.keyring`` file at ``/var/lib/ceph/<fsid>/config/ceph.client.admin.keyring``
on the specified host(s)
- store a copy of the keyring file on the specified host(s)
- update the ``ceph.conf`` file as needed (e.g., due to a change in the cluster Monitors)
- update the keyring file if the entity's key is changed (e.g., via ``ceph
auth ...`` commands)
- ensure that the keyring file has the specified ownership and specified mode
- remove the keyring file when client keyring management is disabled
- remove the keyring file from old hosts if the keyring placement spec is
updated (as needed)
Listing Client Keyrings
-----------------------
To see the list of client keyrings are currently under management, run the following command:
.. prompt:: bash #
ceph orch client-keyring ls
Enabling Management of a Keyring File
-------------------------------------
To enable management of a keyring file, run a command of the following form:
.. prompt:: bash #
ceph orch client-keyring set <entity> <placement> [--mode=<mode>] [--owner=<uid>.<gid>] [--path=<path>]
- By default, the ``path`` is ``/etc/ceph/client.{entity}.keyring``, which is
where Ceph looks by default. Be careful when specifying alternate locations,
as existing files may be overwritten.
- A placement of ``*`` (all hosts) is common.
- The mode defaults to ``0600`` and ownership to ``0:0`` (user root, group root).
For example, to create a ``client.rbd`` key and deploy it to hosts with the
``rbd-client`` label and make it group readable by uid/gid 107 (qemu), run the
following commands:
.. prompt:: bash #
ceph auth get-or-create-key client.rbd mon 'profile rbd' mgr 'profile rbd' osd 'profile rbd pool=my_rbd_pool'
ceph orch client-keyring set client.rbd label:rbd-client --owner 107:107 --mode 640
The resulting keyring file is:
.. code-block:: console
-rw-r-----. 1 qemu qemu 156 Apr 21 08:47 /etc/ceph/client.client.rbd.keyring
By default, cephadm will also manage ``/etc/ceph/ceph.conf`` on hosts where it writes the keyrings.
This feature can be suppressed by passing ``--no-ceph-conf`` when setting the keyring.
.. prompt:: bash #
ceph orch client-keyring set client.foo label:foo 0:0 --no-ceph-conf
Disabling Management of a Keyring File
--------------------------------------
To disable management of a keyring file, run a command of the following form:
.. prompt:: bash #
ceph orch client-keyring rm <entity>
.. note::
This deletes any keyring files for this entity that were previously written
to cluster nodes.
.. _etc_ceph_conf_distribution:
Management of ``/etc/ceph/ceph.conf``
=====================================
Distributing ``ceph.conf`` to Hosts that Have no Keyrings
---------------------------------------------------------
It might be useful to distribute ``ceph.conf`` files to hosts without an
associated client keyring file. By default, cephadm deploys only a
``ceph.conf`` file to hosts where a client keyring is also distributed (see
:ref:`client_keyrings_and_configs` above). To write config files to hosts
without client keyrings, run the following command:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/manage_etc_ceph_ceph_conf true
.. _ceph_conf_distribution_label:
Using Placement Specs to Specify which Hosts Get ``ceph.conf``
--------------------------------------------------------------
By default, the configs are written to all hosts (i.e., those listed by ``ceph
orch host ls``). To specify which hosts get a ``ceph.conf``, run a command of
the following form:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/manage_etc_ceph_ceph_conf_hosts <placement spec>
For example, to distribute configs to hosts with the ``bare_config`` label, run
the following command:
.. prompt:: bash #
ceph config set mgr mgr/cephadm/manage_etc_ceph_ceph_conf_hosts label:bare_config
See :ref:`orchestrator-cli-placement-spec` for more information about placement specs.
Limiting Passwordless Sudo Access
=================================
By default, the cephadm install guide recommends enabling passwordless
``sudo`` for the cephadm user. This option is the most flexible and
future-proof but may not be preferred in all environments. An administrator can
restrict ``sudo`` to only running an exact list of commands without password
access. Note that this list may change between Ceph versions and
administrators choosing this option should read the release notes and review
this list in the destination version of the Ceph documentation. If the list
differs one must extend the list of passwordless ``sudo`` commands prior to
upgrade.
Commands requiring passwordless sudo support:
- ``chmod``
- ``chown``
- ``ls``
- ``mkdir``
- ``mv``
- ``rm``
- ``sysctl``
- ``touch``
- ``true``
- ``which`` (see note)
- ``/usr/bin/cephadm`` or python executable (see note)
.. note:: Typically cephadm will execute ``which`` to determine which ``python3``
command is available and then use the command returned by ``which`` in
subsequent commands.
Before configuring ``sudo`` run ``which python3`` to determine what
python command to add to the ``sudo`` configuration.
In some rare configurations ``/usr/bin/cephadm`` will be used instead.
Configuring the ``sudoers`` file can be performed using a tool like ``visudo``
and adding or replacing a user configuration line such as the following:
.. code-block:: console
# assuming the cephadm user is named "ceph"
ceph ALL=(ALL) NOPASSWD:/usr/bin/chmod,/usr/bin/chown,/usr/bin/ls,/usr/bin/mkdir,/usr/bin/mv,/usr/bin/rm,/usr/sbin/sysctl,/usr/bin/touch,/usr/bin/true,/usr/bin/which,/usr/bin/cephadm,/usr/bin/python3
Purging a cluster
=================
.. danger:: THIS OPERATION WILL DESTROY ALL DATA STORED IN THIS CLUSTER!
In order to destroy a cluster and delete all data stored in this cluster, disable
cephadm to stop all orchestration operations (so we avoid deploying new daemons):
.. prompt:: bash #
ceph mgr module disable cephadm
Then verify the FSID of the cluster:
.. prompt:: bash #
ceph fsid
Purge Ceph daemons from all hosts in the cluster:
.. prompt:: bash #
# For each host:
cephadm rm-cluster --force --zap-osds --fsid <fsid>
Replacing a Device
==================
The ``ceph orch device replace`` command automates the process of replacing the underlying device of an OSD.
Previously, this process required manual intervention at various stages.
With this new command, all necessary operations are performed automatically, streamlining the replacement process
and improving the overall user experience.
.. note:: This supports only LVM-based deployed OSD(s).
.. prompt:: bash #
ceph orch device replace <host> <device-path>
If the device being replaced is shared by multiple OSDs (e.g., DB/WAL
device shared by multiple OSDs), the orchestrator will warn you:
.. prompt:: bash # auto
# ceph orch device replace osd-1 /dev/vdd
Error EINVAL: /dev/vdd is a shared device.
Replacing /dev/vdd implies destroying OSD(s): ['0', '1'].
Please, *be very careful*, this can be a very dangerous operation.
If you know what you are doing, pass --yes-i-really-mean-it
If you know what you are doing, you can go ahead and pass ``--yes-i-really-mean-it``:
.. prompt:: bash # auto
# ceph orch device replace osd-1 /dev/vdd --yes-i-really-mean-it
Scheduled to destroy osds: ['6', '7', '8'] and mark /dev/vdd as being replaced.
``cephadm`` will execute ``ceph-volume`` to zap and destroy all related devices
and mark the corresponding OSD as ``destroyed`` so the different OSD(s) ID(s)
will be preserved:
.. prompt:: bash # auto
# ceph osd tree
ID CLASS WEIGHT TYPE NAME STATUS REWEIGHT PRI-AFF
-1 0.97659 root default
-3 0.97659 host devel-1
0 hdd 0.29300 osd.0 destroyed 1.00000 1.00000
1 hdd 0.29300 osd.1 destroyed 1.00000 1.00000
2 hdd 0.19530 osd.2 up 1.00000 1.00000
3 hdd 0.19530 osd.3 up 1.00000 1.00000
The device being replaced is finally seen as ``being replaced``
preventing ``cephadm`` from redeploying the OSDs too fast:
.. prompt:: bash # auto
# ceph orch device ls
HOST PATH TYPE DEVICE ID SIZE AVAILABLE REFRESHED REJECT REASONS
osd-1 /dev/vdb hdd 200G Yes 13s ago
osd-1 /dev/vdc hdd 200G Yes 13s ago
osd-1 /dev/vdd hdd 200G Yes 13s ago Is being replaced
osd-1 /dev/vde hdd 200G No 13s ago Has a FileSystem, Insufficient space (<10 extents) on vgs, LVM detected
osd-1 /dev/vdf hdd 200G No 13s ago Has a FileSystem, Insufficient space (<10 extents) on vgs, LVM detected
If for any reason you need to clear the 'device replace header' on a device,
run a command of the following form:
.. prompt:: bash # auto
# ceph orch device replace <host> <device> --clear
For example:
.. prompt:: bash # auto
# ceph orch device replace devel-1 /dev/vdk --clear
Replacement header cleared on /dev/vdk
Cephadm will then redeploy the OSD service spec within a few minutes
(unless the service is set to ``unmanaged``).