From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sage Weil Subject: removing cluster name support Date: Thu, 8 Jun 2017 19:37:23 +0000 (UTC) Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: ceph-users-bounces-idqoXFIVOFJgJs9I8MT0rw@public.gmane.org Sender: "ceph-users" To: ceph-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ceph-users-Qp0mS5GaXlQ@public.gmane.org List-Id: ceph-devel.vger.kernel.org At CDM yesterday we talked about removing the ability to name your ceph clusters. There are a number of hurtles that make it difficult to fully get rid of this functionality, not the least of which is that some (many?) deployed clusters make use of it. We decided that the most we can do at this point is remove support for it in ceph-deploy and ceph-ansible so that no new clusters or deployed nodes use it. The first PR in this effort: https://github.com/ceph/ceph-deploy/pull/441 Background: The cluster name concept was added to allow multiple clusters to have daemons coexist on the same host. At the type it was a hypothetical requirement for a user that never actually made use of it, and the support is kludgey: - default cluster name is 'ceph' - default config is /etc/ceph/$cluster.conf, so that the normal 'ceph.conf' still works - daemon data paths include the cluster name, /var/lib/ceph/osd/$cluster-$id which is weird (but mostly people are used to it?) - any cli command you want to touch a non-ceph cluster name needs -C $name or --cluster $name passed to it. Also, as of jewel, - systemd only supports a single cluster per host, as defined by $CLUSTER in /etc/{sysconfig,default}/ceph which you'll notice removes support for the original "requirement". Also note that you can get the same effect by specifying the config path explicitly (-c /etc/ceph/foo.conf) along with the various options that substitute $cluster in (e.g., osd_data=/var/lib/ceph/osd/$cluster-$id). Crap preventing us from removing this entirely: - existing daemon directories for existing clusters - various scripts parse the cluster name out of paths Converting an existing cluster "foo" back to "ceph": - rename /etc/ceph/foo.conf -> ceph.conf - rename /var/lib/ceph/*/foo-* -> /var/lib/ceph/*/ceph-* - remove the CLUSTER=foo line in /etc/{default,sysconfig}/ceph - reboot Questions: - Does anybody on the list use a non-default cluster name? - If so, do you have a reason not to switch back to 'ceph'? Thanks! sage