>>> Klaus Wenninger <kwenn...@redhat.com> schrieb am 08.04.2021 um 08:26 in Nachricht <01fe6b6e-690a-2ea7-6218-8545f0b7a...@redhat.com>: > On 4/8/21 8:16 AM, Reid Wahl wrote: >> >> >> On Wed, Apr 7, 2021 at 9:46 PM Strahil Nikolov <hunter86...@yahoo.com >> <mailto:hunter86...@yahoo.com>> wrote: >> >> I always though that the setup is the same, just the node count is >> only one. >> >> I guess you need pcs, corosync + pacemaker. >> If RH is going to support it, they will require fencing. Most >> probably sbd or ipmi are the best candidates. >> >> >> I don't think we do require fencing for single-node clusters. (Anyone >> at Red Hat, feel free to comment.) I vaguely recall an internal >> mailing list or IRC conversation where we discussed this months ago, >> but I can't find it now. I've also checked our support policies >> documentation, and it's not mentioned in the "cluster size" doc or the >> "fencing" doc. >> >> The closest thing I can find is the following, from the cluster size >> doc[1]: >> ~~~ >> RHEL 8.2 and later: Support for 1 or more nodes >> >> * Single node clusters do not support DLM and GFS2 filesystems (as >> they require fencing). >> >> ~~~
Actually I think using DLM and a cluster filesystem for just one single node would be overkill, BUT it should work (if you have planned to extend your 1-node cluster to more nodes at a later time). Fencing for a single-node-cluster just means reboot, so that shouldn't really be the problem. >> >> To me that suggests that fencing isn't required in a single-node >> cluster. Maybe sbd could work (I haven't thought it through), but >> conventional power fencing (e.g., fence_ipmilan) wouldn't. That's >> because most conventional power fencing agents require sending a >> "power on" signal after the "power off" is complete. > And moreover you have to be alive enough to kick off > conventional power fencing to self-fence ;-) > With sbd the hardware-watchdog should kick in. > > Klaus >> >> [1] https://access.redhat.com/articles/3069031 >> <https://access.redhat.com/articles/3069031> >> >> >> Best Regards, >> Strahil Nikolov >> >> On Thu, Apr 8, 2021 at 6:52, d tbsky >> <tbs...@gmail.com <mailto:tbs...@gmail.com>> wrote: >> Hi: >> I found RHEL 8.2 support single node cluster now. but I >> didn't >> find further document to explain the concept. RHEL 8.2 also >> support >> "disaster recovery cluster". so I think maybe a single node >> disaster >> recovery cluster is not bad. >> >> I think corosync is still necessary under single node >> cluster. or >> is there other new style of configuration? >> >> thanks for help! >> _______________________________________________ >> Manage your subscription: >> https://lists.clusterlabs.org/mailman/listinfo/users >> <https://lists.clusterlabs.org/mailman/listinfo/users> >> >> ClusterLabs home: https://www.clusterlabs.org/ >> <https://www.clusterlabs.org/> >> >> _______________________________________________ >> Manage your subscription: >> https://lists.clusterlabs.org/mailman/listinfo/users >> <https://lists.clusterlabs.org/mailman/listinfo/users> >> >> ClusterLabs home: https://www.clusterlabs.org/ >> <https://www.clusterlabs.org/> >> >> >> >> -- >> Regards, >> >> Reid Wahl, RHCA >> Senior Software Maintenance Engineer, Red Hat >> CEE - Platform Support Delivery - ClusterHA >> >> _______________________________________________ >> 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/
