Hi! While it's possible to start with one node and add more nodes later, I would recommend to configure all nodes that should run in the cluster at the same time. Lao it the nodes are physical I would recommend using mostly identical machines. We had some problems when the CPU model was different and VMs should be live-migrated from the newer CPU to the older one. The point why I'm recommending to start with all nodes it testing: You should test fencing and resource migration before going productive. When adding nodes that would mean a downtime, specifically if you find configuration mistakes (not all nodes being equally configured).
Kind regards, Ulrich Windl > -----Original Message----- > From: Users <users-boun...@clusterlabs.org> On Behalf Of Eugen Block > Sent: Saturday, August 2, 2025 2:00 PM > To: Cluster Labs - All topics related to open-source clustering welcomed > <users@clusterlabs.org> > Subject: [EXT] Re: [ClusterLabs] Creating pacemaker cluster starting with one > node > > Since we are familiar with SUSE products, we based our deployment on > the SUSE High Availability docs: > > https://documentation.suse.com/en-us/sle-ha/15-SP7/single-html/SLE-HA- > installation/index.html > > So in short, we run „crm cluster init“ on the bootstrap node, and when > everything works as expected, „crm node join“ on the further nodes. Of > course, there’s some more details required, like the corosync config, > csync2 etc. > > Our own cluster was based on openSUSE, but when SUSE discontinued the > OpenStack product, we couldn’t upgrade anymore on openSUSE. So last > year, we reinstalled our cloud on Ubuntu by redeploying a pacemaker > cluster (single node), brought OpenStack back up, then joined the > second server. And it works great, we’re just waiting for the latest > updates to arrive in the distro for better systemd management. > > Zitat von Andreas Mock <andreas.m...@drumedar.de>: > > > Hi Thomas, hi Eugen, > > > > thank you for the reply. > > > > Is there anywhere a howto to bootstrap such an one node cluster? > > > > Best regards > > Andreas > > > > > > - > > -----Ursprüngliche Nachricht----- > > Von: Users <users-boun...@clusterlabs.org> Im Auftrag von Eugen Block > > Gesendet: Samstag, 2. August 2025 11:18 > > An: Cluster Labs - All topics related to open-source clustering > > welcomed <users@clusterlabs.org> > > Betreff: Re: [ClusterLabs] Creating pacemaker cluster starting with one > node > > > > Hi, > > > > that's how we usually set up our Openstack cluster(s). We bootstrap > > our first node so we have a single-node pacemaker cluster running > > all Openstack control services, then "join" the other control nodes, > > expanding the cluster. > > I'd recommend to practice in a test cluster, that has helped me a lot! > > > > Regards, > > Eugen > > > > Zitat von Tomas Jelinek <tojel...@redhat.com>: > > > >> Hi Andreas, > >> > >> From the point of view of pcs, pacemaker and corosync, it is possible > >> to create a one-node cluster, run resources in it, and add another > >> node afterwards. Obviously, when the single node is lost for whatever > >> reason, there is no other node to run the resources. > >> > >> You should also consider whether the cluster's workload supports this > >> and what steps are necessary to make it work in this scenario. > >> > >> Regards, > >> Tomas > >> > >> > >> Dne 31. 07. 25 v 8:46 Andreas Mock napsal(a): > >>> Hi all, > >>> > >>> I have to upgrade an old pacemaker cluster consisting of two nodes. > >>> (There is no chance of rolling update). > >>> > >>> Is it possible to create a pacemaker “cluster” starting with only one > >>> node and afterwards attach the second node? > >>> > >>> Best regards > >>> > >>> Andreas > >>> > >>> > >>> _______________________________________________ > >>> Manage your subscription: > >>> https://lists.clusterlabs.org/mailman/listinfo/users > >>> > >>> ClusterLabs home: https://www.clusterlabs.org/ > >> > >> _______________________________________________ > >> Manage your subscription: > >> https://lists.clusterlabs.org/mailman/listinfo/users > >> > >> ClusterLabs home: https://www.clusterlabs.org/ > > > > > > > > _______________________________________________ > > Manage your subscription: > > https://lists.clusterlabs.org/mailman/listinfo/users > > > > ClusterLabs home: https://www.clusterlabs.org/ > > _______________________________________________ > > Manage your subscription: > > https://lists.clusterlabs.org/mailman/listinfo/users > > > > ClusterLabs home: https://www.clusterlabs.org/ > > > > _______________________________________________ > Manage your subscription: > https://lists.clusterlabs.org/mailman/listinfo/users > > ClusterLabs home: https://www.clusterlabs.org/ _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
