ceph/doc/cephadm/adoption.rst

   1 .. _cephadm-adoption:
   2
   3 Converting an existing cluster to cephadm
   4 =========================================
   5
   6 It is possible to convert some existing clusters so that they can be managed
   7 with ``cephadm``. This statment applies to some clusters that were deployed
   8 with ``ceph-deploy``, ``ceph-ansible``, or ``DeepSea``.
   9
  10 This section of the documentation explains how to determine whether your
  11 clusters can be converted to a state in which they can be managed by
  12 ``cephadm`` and how to perform those conversions.
  13
  14 Limitations
  15 -----------
  16
  17 * Cephadm works only with BlueStore OSDs. FileStore OSDs that are in your
  18   cluster cannot be managed with ``cephadm``.
  19
  20 Preparation
  21 -----------
  22
  23 #. Make sure that the ``cephadm`` command line tool is available on each host
  24    in the existing cluster.  See :ref:`get-cephadm` to learn how.
  25
  26 #. Prepare each host for use by ``cephadm`` by running this command:
  27
  28    .. prompt:: bash #
  29
  30       cephadm prepare-host
  31
  32 #. Choose a version of Ceph to use for the conversion. This procedure will work
  33    with any release of Ceph that is Octopus (15.2.z) or later, inclusive.  The
  34    latest stable release of Ceph is the default. You might be upgrading from an
  35    earlier Ceph release at the same time that you're performing this
  36    conversion; if you are upgrading from an earlier release, make sure to
  37    follow any upgrade-releated instructions for that release.
  38
  39    Pass the image to cephadm with the following command:
  40
  41    .. prompt:: bash #
  42
  43       cephadm --image $IMAGE <rest of command goes here>
  44
  45    The conversion begins.
  46
  47 #. Confirm that the conversion is underway by running ``cephadm ls`` and
  48    making sure that the style of the daemons is changed:
  49
  50    .. prompt:: bash #
  51
  52       cephadm ls
  53
  54    Before starting the converstion process, ``cephadm ls`` shows all existing
  55    daemons to have a style of ``legacy``. As the adoption process progresses,
  56    adopted daemons will appear with a style of ``cephadm:v1``.
  57
  58
  59 Adoption process
  60 ----------------
  61
  62 #. Make sure that the ceph configuration has been migrated to use the cluster
  63    config database.  If the ``/etc/ceph/ceph.conf`` is identical on each host,
  64    then the following command can be run on one single host and will affect all
  65    hosts:
  66
  67    .. prompt:: bash #
  68
  69       ceph config assimilate-conf -i /etc/ceph/ceph.conf
  70
  71    If there are configuration variations between hosts, you will need to repeat
  72    this command on each host. During this adoption process, view the cluster's
  73    configuration to confirm that it is complete by running the following
  74    command:
  75
  76    .. prompt:: bash #
  77
  78       ceph config dump
  79
  80 #. Adopt each monitor:
  81
  82    .. prompt:: bash #
  83
  84       cephadm adopt --style legacy --name mon.<hostname>
  85
  86    Each legacy monitor should stop, quickly restart as a cephadm
  87    container, and rejoin the quorum.
  88
  89 #. Adopt each manager:
  90
  91    .. prompt:: bash #
  92
  93       cephadm adopt --style legacy --name mgr.<hostname>
  94
  95 #. Enable cephadm:
  96
  97    .. prompt:: bash #
  98
  99       ceph mgr module enable cephadm
 100       ceph orch set backend cephadm
 101
 102 #. Generate an SSH key:
 103
 104    .. prompt:: bash #
 105
 106       ceph cephadm generate-key
 107       ceph cephadm get-pub-key > ~/ceph.pub
 108
 109 #. Install the cluster SSH key on each host in the cluster:
 110
 111    .. prompt:: bash #
 112
 113       ssh-copy-id -f -i ~/ceph.pub root@<host>
 114
 115    .. note::
 116      It is also possible to import an existing ssh key. See
 117      :ref:`ssh errors <cephadm-ssh-errors>` in the troubleshooting
 118      document for instructions that describe how to import existing
 119      ssh keys.
 120
 121 #. Tell cephadm which hosts to manage:
 122
 123    .. prompt:: bash #
 124
 125       ceph orch host add <hostname> [ip-address]
 126
 127    This will perform a ``cephadm check-host`` on each host before adding it;
 128    this check ensures that the host is functioning properly. The IP address
 129    argument is recommended; if not provided, then the host name will be resolved
 130    via DNS.
 131
 132 #. Verify that the adopted monitor and manager daemons are visible:
 133
 134    .. prompt:: bash #
 135
 136       ceph orch ps
 137
 138 #. Adopt all OSDs in the cluster:
 139
 140    .. prompt:: bash #
 141
 142       cephadm adopt --style legacy --name <name>
 143
 144    For example:
 145
 146    .. prompt:: bash #
 147
 148       cephadm adopt --style legacy --name osd.1
 149       cephadm adopt --style legacy --name osd.2
 150
 151 #. Redeploy MDS daemons by telling cephadm how many daemons to run for
 152    each file system. List file systems by name with the command ``ceph fs
 153    ls``. Run the following command on the master nodes to redeploy the MDS
 154    daemons:
 155
 156    .. prompt:: bash #
 157
 158       ceph orch apply mds <fs-name> [--placement=<placement>]
 159
 160    For example, in a cluster with a single file system called `foo`:
 161
 162    .. prompt:: bash #
 163
 164       ceph fs ls
 165
 166    .. code-block:: bash
 167
 168       name: foo, metadata pool: foo_metadata, data pools: [foo_data ]
 169
 170    .. prompt:: bash #
 171
 172       ceph orch apply mds foo 2
 173
 174    Confirm that the new MDS daemons have started:
 175
 176    .. prompt:: bash #
 177
 178       ceph orch ps --daemon-type mds
 179
 180    Finally, stop and remove the legacy MDS daemons:
 181
 182    .. prompt:: bash #
 183
 184       systemctl stop ceph-mds.target
 185       rm -rf /var/lib/ceph/mds/ceph-*
 186
 187 #. Redeploy RGW daemons. Cephadm manages RGW daemons by zone. For each
 188    zone, deploy new RGW daemons with cephadm:
 189
 190    .. prompt:: bash #
 191
 192       ceph orch apply rgw <svc_id> [--realm=<realm>] [--zone=<zone>] [--port=<port>] [--ssl] [--placement=<placement>]
 193
 194    where *<placement>* can be a simple daemon count, or a list of
 195    specific hosts (see :ref:`orchestrator-cli-placement-spec`), and the
 196    zone and realm arguments are needed only for a multisite setup.
 197
 198    After the daemons have started and you have confirmed that they are
 199    functioning, stop and remove the old, legacy daemons:
 200
 201    .. prompt:: bash #
 202
 203       systemctl stop ceph-rgw.target
 204       rm -rf /var/lib/ceph/radosgw/ceph-*
 205
 206 #. Check the output of the command ``ceph health detail`` for cephadm warnings
 207    about stray cluster daemons or hosts that are not yet managed by cephadm.