1 ============================
2 Deploying a new Ceph cluster
3 ============================
5 Cephadm creates a new Ceph cluster by "bootstrapping" on a single
6 host, expanding the cluster to encompass any additional hosts, and
7 then deploying the needed services.
12 .. _cephadm-host-requirements:
19 - Podman or Docker for running containers
20 - Time synchronization (such as chrony or NTP)
21 - LVM2 for provisioning storage devices
23 Any modern Linux distribution should be sufficient. Dependencies
24 are installed automatically by the bootstrap process below.
26 See the section :ref:`Compatibility With Podman
27 Versions<cephadm-compatibility-with-podman>` for a table of Ceph versions that
28 are compatible with Podman. Not every version of Podman is compatible with
38 The ``cephadm`` command can
40 #. bootstrap a new cluster
41 #. launch a containerized shell with a working Ceph CLI
42 #. aid in debugging containerized Ceph daemons
44 There are two ways to install ``cephadm``:
46 #. a :ref:`curl-based installation<cephadm_install_curl>` method
47 #. :ref:`distribution-specific installation methods<cephadm_install_distros>`
49 .. _cephadm_install_curl:
51 curl-based installation
52 -----------------------
54 * Use ``curl`` to fetch the most recent version of the
60 curl --silent --remote-name --location https://github.com/ceph/ceph/raw/|stable-release|/src/cephadm/cephadm
62 Make the ``cephadm`` script executable:
68 This script can be run directly from the current directory:
72 ./cephadm <arguments...>
74 * Although the standalone script is sufficient to get a cluster started, it is
75 convenient to have the ``cephadm`` command installed on the host. To install
76 the packages that provide the ``cephadm`` command, run the following
82 ./cephadm add-repo --release |stable-release|
85 Confirm that ``cephadm`` is now in your PATH by running ``which``:
91 A successful ``which cephadm`` command will return this:
97 .. _cephadm_install_distros:
99 distribution-specific installations
100 -----------------------------------
102 .. important:: The methods of installing ``cephadm`` in this section are distinct from the curl-based method above. Use either the curl-based method above or one of the methods in this section, but not both the curl-based method and one of these.
104 Some Linux distributions may already include up-to-date Ceph packages. In
105 that case, you can install cephadm directly. For example:
111 apt install -y cephadm
117 dnf -y install cephadm
123 zypper install -y cephadm
127 Bootstrap a new cluster
128 =======================
130 What to know before you bootstrap
131 ---------------------------------
133 The first step in creating a new Ceph cluster is running the ``cephadm
134 bootstrap`` command on the Ceph cluster's first host. The act of running the
135 ``cephadm bootstrap`` command on the Ceph cluster's first host creates the Ceph
136 cluster's first "monitor daemon", and that monitor daemon needs an IP address.
137 You must pass the IP address of the Ceph cluster's first host to the ``ceph
138 bootstrap`` command, so you'll need to know the IP address of that host.
140 .. note:: If there are multiple networks and interfaces, be sure to choose one
141 that will be accessible by any host accessing the Ceph cluster.
143 Running the bootstrap command
144 -----------------------------
146 Run the ``ceph bootstrap`` command:
150 cephadm bootstrap --mon-ip *<mon-ip>*
154 * Create a monitor and manager daemon for the new cluster on the local
156 * Generate a new SSH key for the Ceph cluster and add it to the root
157 user's ``/root/.ssh/authorized_keys`` file.
158 * Write a copy of the public key to ``/etc/ceph/ceph.pub``.
159 * Write a minimal configuration file to ``/etc/ceph/ceph.conf``. This
160 file is needed to communicate with the new cluster.
161 * Write a copy of the ``client.admin`` administrative (privileged!)
162 secret key to ``/etc/ceph/ceph.client.admin.keyring``.
163 * Add the ``_admin`` label to the bootstrap host. By default, any host
164 with this label will (also) get a copy of ``/etc/ceph/ceph.conf`` and
165 ``/etc/ceph/ceph.client.admin.keyring``.
167 Further information about cephadm bootstrap
168 -------------------------------------------
170 The default bootstrap behavior will work for most users. But if you'd like
171 immediately to know more about ``cephadm bootstrap``, read the list below.
173 Also, you can run ``cephadm bootstrap -h`` to see all of ``cephadm``'s
176 * By default, Ceph daemons send their log output to stdout/stderr, which is picked
177 up by the container runtime (docker or podman) and (on most systems) sent to
178 journald. If you want Ceph to write traditional log files to ``/var/log/ceph/$fsid``,
179 use the ``--log-to-file`` option during bootstrap.
181 * Larger Ceph clusters perform better when (external to the Ceph cluster)
182 public network traffic is separated from (internal to the Ceph cluster)
183 cluster traffic. The internal cluster traffic handles replication, recovery,
184 and heartbeats between OSD daemons. You can define the :ref:`cluster
185 network<cluster-network>` by supplying the ``--cluster-network`` option to the ``bootstrap``
186 subcommand. This parameter must define a subnet in CIDR notation (for example
187 ``10.90.90.0/24`` or ``fe80::/64``).
189 * ``cephadm bootstrap`` writes to ``/etc/ceph`` the files needed to access
190 the new cluster. This central location makes it possible for Ceph
191 packages installed on the host (e.g., packages that give access to the
192 cephadm command line interface) to find these files.
194 Daemon containers deployed with cephadm, however, do not need
195 ``/etc/ceph`` at all. Use the ``--output-dir *<directory>*`` option
196 to put them in a different directory (for example, ``.``). This may help
197 avoid conflicts with an existing Ceph configuration (cephadm or
198 otherwise) on the same host.
200 * You can pass any initial Ceph configuration options to the new
201 cluster by putting them in a standard ini-style configuration file
202 and using the ``--config *<config-file>*`` option. For example::
204 $ cat <<EOF > initial-ceph.conf
206 osd crush chooseleaf type = 0
208 $ ./cephadm bootstrap --config initial-ceph.conf ...
210 * The ``--ssh-user *<user>*`` option makes it possible to choose which ssh
211 user cephadm will use to connect to hosts. The associated ssh key will be
212 added to ``/home/*<user>*/.ssh/authorized_keys``. The user that you
213 designate with this option must have passwordless sudo access.
215 * If you are using a container on an authenticated registry that requires
216 login, you may add the three arguments:
218 #. ``--registry-url <url of registry>``
220 #. ``--registry-username <username of account on registry>``
222 #. ``--registry-password <password of account on registry>``
226 * ``--registry-json <json file with login info>``
228 Cephadm will attempt to log in to this registry so it can pull your container
229 and then store the login info in its config database. Other hosts added to
230 the cluster will then also be able to make use of the authenticated registry.
232 .. _cephadm-enable-cli:
237 Cephadm does not require any Ceph packages to be installed on the
238 host. However, we recommend enabling easy access to the ``ceph``
239 command. There are several ways to do this:
241 * The ``cephadm shell`` command launches a bash shell in a container
242 with all of the Ceph packages installed. By default, if
243 configuration and keyring files are found in ``/etc/ceph`` on the
244 host, they are passed into the container environment so that the
245 shell is fully functional. Note that when executed on a MON host,
246 ``cephadm shell`` will infer the ``config`` from the MON container
247 instead of using the default configuration. If ``--mount <path>``
248 is given, then the host ``<path>`` (file or directory) will appear
249 under ``/mnt`` inside the container:
255 * To execute ``ceph`` commands, you can also run commands like this:
259 cephadm shell -- ceph -s
261 * You can install the ``ceph-common`` package, which contains all of the
262 ceph commands, including ``ceph``, ``rbd``, ``mount.ceph`` (for mounting
263 CephFS file systems), etc.:
268 cephadm add-repo --release |stable-release|
269 cephadm install ceph-common
271 Confirm that the ``ceph`` command is accessible with:
278 Confirm that the ``ceph`` command can connect to the cluster and also
288 Next, add all hosts to the cluster by following :ref:`cephadm-adding-hosts`.
290 By default, a ``ceph.conf`` file and a copy of the ``client.admin`` keyring
291 are maintained in ``/etc/ceph`` on all hosts with the ``_admin`` label, which is initially
292 applied only to the bootstrap host. We usually recommend that one or more other hosts be
293 given the ``_admin`` label so that the Ceph CLI (e.g., via ``cephadm shell``) is easily
294 accessible on multiple hosts. To add the ``_admin`` label to additional host(s),
298 ceph orch host label add *<host>* _admin
300 Adding additional MONs
301 ======================
303 A typical Ceph cluster has three or five monitor daemons spread
304 across different hosts. We recommend deploying five
305 monitors if there are five or more nodes in your cluster.
307 Please follow :ref:`deploy_additional_monitors` to deploy additional MONs.
312 To add storage to the cluster, either tell Ceph to consume any
313 available and unused device:
317 ceph orch apply osd --all-available-devices
319 Or See :ref:`cephadm-deploy-osds` for more detailed instructions.
324 To use the *Ceph Filesystem*, follow :ref:`orchestrator-cli-cephfs`.
326 To use the *Ceph Object Gateway*, follow :ref:`cephadm-deploy-rgw`.
328 To use *NFS*, follow :ref:`deploy-cephadm-nfs-ganesha`
330 To use *iSCSI*, follow :ref:`cephadm-iscsi`
333 .. _cluster network: ../rados/configuration/network-config-ref#cluster-network