From 872668a9b37ee5a0171c37b3b6f0f4d605ee54a2 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 25 May 2021 12:14:39 -0400 Subject: [PATCH] doc/cephadm: remove any reference to the use of DNS or /etc/hosts Signed-off-by: Sage Weil --- doc/cephadm/adoption.rst | 4 ++-- doc/cephadm/host-management.rst | 31 ++++++++++++------------------- 2 files changed, 14 insertions(+), 21 deletions(-) diff --git a/doc/cephadm/adoption.rst b/doc/cephadm/adoption.rst index 61648fd9e16..db4fded3981 100644 --- a/doc/cephadm/adoption.rst +++ b/doc/cephadm/adoption.rst @@ -126,8 +126,8 @@ Adoption process This will perform a ``cephadm check-host`` on each host before adding it; this check ensures that the host is functioning properly. The IP address - argument is required only if DNS does not allow you to connect to each host - by its short name. + argument is recommended; if not provided, then the host name will be resolved + via DNS. #. Verify that the adopted monitor and manager daemons are visible: diff --git a/doc/cephadm/host-management.rst b/doc/cephadm/host-management.rst index 012dafc3388..bcf626752fc 100644 --- a/doc/cephadm/host-management.rst +++ b/doc/cephadm/host-management.rst @@ -37,14 +37,18 @@ To add each new host to the cluster, perform two steps: .. prompt:: bash # - ceph orch host add *newhost* [* ...*] + ceph orch host add ** [**] [* ...*] For example: .. prompt:: bash # - ceph orch host add host2 - ceph orch host add host3 + ceph orch host add host2 10.10.0.102 + ceph orch host add host3 10.10.0.103 + + It is best to explicitly provide the host IP address. If an IP is + not provided, then the host name will be immediately resolved via + DNS and that IP will be used. One or more labels can also be included to immediately label the new host. For example, by default the ``_admin`` label will make @@ -53,7 +57,7 @@ To add each new host to the cluster, perform two steps: .. prompt:: bash # - ceph orch host add host4 _admin + ceph orch host add host4 10.10.0.104 --labels _admin .. _cephadm-removing-hosts: @@ -174,21 +178,21 @@ Many hosts can be added at once using --- service_type: host - addr: node-00 hostname: node-00 + addr: 192.168.0.10 labels: - example1 - example2 --- service_type: host - addr: node-01 hostname: node-01 + addr: 192.168.0.11 labels: - grafana --- service_type: host - addr: node-02 hostname: node-02 + addr: 192.168.0.12 This can be combined with service specifications (below) to create a cluster spec file to deploy a whole cluster in one command. see ``cephadm bootstrap --apply-spec`` @@ -286,23 +290,12 @@ There are two ways to customize this configuration for your environment: Fully qualified domain names vs bare host names =============================================== -cephadm has very minimal requirements when it comes to resolving host -names etc. When cephadm initiates an ssh connection to a remote host, -the host name can be resolved in four different ways: - -- a custom ssh config resolving the name to an IP -- via explicitly providing an IP address to cephadm: ``ceph orch host add `` -- automatic name resolution via DNS. - -Ceph itself uses the command ``hostname`` to determine the name of the -current host. - .. note:: cephadm demands that the name of the host given via ``ceph orch host add`` equals the output of ``hostname`` on remote hosts. -Otherwise cephadm can't be sure, the host names returned by +Otherwise cephadm can't be sure that names returned by ``ceph * metadata`` match the hosts known to cephadm. This might result in a :ref:`cephadm-stray-host` warning. -- 2.39.5