Hello Sam, > For Mons and Mgrs, what stuff do I need to retain across the OS upgrade to have things "just work" [since they're relatively stateless, I assume mostly the /etc/ceph/ stuff and ceph cluster keys?] > For the MDS, I assume it's similar to MGRS? The MDS, IIRC, mainly works as a caching layer so I assume there's not much state that can be lost permanently? The stuff under "/var/lib/ceph" shall be migrated to new OS installation. When I performed the transition from EL7+Nautilus to EL8+Octopus for one of the nodes of the lab cluster, the biggest challenge was to tackle various problems found in Ansible (ceph-ansible is used for deployment and management), especially what I was doing is a node-by-node transition rather than a whole cluster upgrade (which sounds more risky). Regards. ------------------ Original ------------------ From: "Sam Skipsey"<aoanla@xxxxxxxxx>; Date: Thu, Sep 7, 2023 11:52 PM To: "ceph-users"<ceph-users@xxxxxxx>; Subject: Upgrading OS [and ceph release] nondestructively for oldish Ceph cluster Hello all, We've had a Nautilus [latest releases] cluster for some years now, and are planning the upgrade process - both moving off Centos7 [ideally to a RHEL9 compatible spin like Alma 9 or Rocky 9] and also moving to a newer Ceph release [ideally Pacific or higher to avoid too many later upgrades needed]. As far as ceph release upgrades go, I understand the process in general. What I'm less certain about (and more nervous about from a potential data loss perspective) is the OS upgrade. For Ceph bluestore OSDs, I assume all the relevant metadata is on the OSD disk [or on the separate disk configured for RocksDB etc if you have nvme], and none is on the OS itself? For Mons and Mgrs, what stuff do I need to retain across the OS upgrade to have things "just work" [since they're relatively stateless, I assume mostly the /etc/ceph/ stuff and ceph cluster keys?] For the MDS, I assume it's similar to MGRS? The MDS, IIRC, mainly works as a caching layer so I assume there's not much state that can be lost permanently? Has anyone gone through this process who would be happy to share their experience? (There's not a lot on this on the wider internet - lots on upgrading ceph, much less on the OS) Sam _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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