Ah, forgot to mention that our compute and control nodes (OpenStack) also mount the CephFS for live migration purposes (Nova) and image to volume conversion (Cinder), and they apparently also report their feature set as "luminous".
Am Di., 3. Feb. 2026 um 08:15 Uhr schrieb Eugen Block via ceph-users < [email protected]>: > Hi Janek, > > this 'ceph features' output that you're probably referring to (or maybe > 'ceph tell mon.X sessions') comes up every now and then, for example [0], > [1], [2]. I also still don't have a definitive answer, unfortunately. But > from my understanding those are compatibility features that don't > necessarily reflect the actual ceph version. For example, I have a test > cluster with tentacle: > > tentacle:~ # ceph versions > { > "mon": { > "ceph version 20.2.0 (69f84cc2651aa259a15bc192ddaabd3baba07489) > tentacle (stable - RelWithDebInfo)": 1 > }, > "mgr": { > "ceph version 20.2.0 (69f84cc2651aa259a15bc192ddaabd3baba07489) > tentacle (stable - RelWithDebInfo)": 2 > }, > "osd": { > "ceph version 20.2.0 (69f84cc2651aa259a15bc192ddaabd3baba07489) > tentacle (stable - RelWithDebInfo)": 3 > }, > "mds": { > "ceph version 20.2.0 (69f84cc2651aa259a15bc192ddaabd3baba07489) > tentacle (stable - RelWithDebInfo)": 1 > }, > "overall": { > "ceph version 20.2.0 (69f84cc2651aa259a15bc192ddaabd3baba07489) > tentacle (stable - RelWithDebInfo)": 7 > } > } > > but 'ceph features' shows squid: > > tentacle:~ # ceph features > { > "mon": [ > { > "features": "0x3f07fffffffdffff", > "release": "squid", > "num": 1 > } > ], > "mds": [ > { > "features": "0x3f07fffffffdffff", > "release": "squid", > "num": 1 > } > ], > "osd": [ > { > "features": "0x3f07fffffffdffff", > "release": "squid", > "num": 3 > } > ], > ... > > And this cluster also has "luminous" clients connected although I enforced > "squid" with 'ceph osd set-require-min-compat-client squid'. In our > production cluster I haven't enforced that, it is still running with > luminous as min-compat-client because we actually do have a couple of older > clients and don't want to risk anything, but we're going to have to deal > with them at some point. > > Anyway, I'm not recommending to enforce the require-min-compat-client > update, I'd rather suggest to set up a test cluster with a couple of your > typical clients maybe, and then see if they successfully connect. I did the > same in my lab virtual environment that resembles our prod. cluster > (OpenStack with Ceph), there I enforced "reef" as min-compat-client and new > mounts from Ubuntu machines (24.04, kernel 6.8.0) with Ceph 19.2.1 packages > still report luminous on a CephFS mount. But the mount works, so I assume > that everything is okay in the lab. But I'm still not feeling confident > enough to recommend you to update it. ;-) > Hopefully someone else chimes in and contradicts or confirms my > statement(s). > > Regards, > Eugen > > [0] > > https://lists.ceph.io/hyperkitty/list/[email protected]/thread/A4IWXINDBM6KI4DJXC62TNE2Y37P2EM2/#36GQ5PJ74JIYUGTS2SSVYBXKIQF7WRN5 > [1] > > https://lists.ceph.io/hyperkitty/list/[email protected]/thread/RVND3Y3Z7FDR4ENHKOSDHFJ5XBZJR547/#YKJPMWJAL7X4T4UIQ6JRYV2LKG6G2JND > [2] > > https://lists.ceph.io/hyperkitty/list/[email protected]/thread/WSADGYBR7PLUBWSEBTJDKETU534R4FX4/#FNCJBSL7IB2HAQZPFWO4P6O6ELOMKYYX > > Am Mi., 28. Jan. 2026 um 09:16 Uhr schrieb Janek Bevendorff via ceph-users > < > [email protected]>: > > > I just noticed that this applies to RBD clients as well. How is this > > supposed to work? Can you use only radosgw and ceph-fuse if you want to > > use upmap-read? It seems strange to me that the most central Ceph > > systems don't work with these new features. > > > > > > On 26/01/2026 18:55, Janek Bevendorff via ceph-users wrote: > > > Hi, > > > > > > Is there a way to use the new upmap-read balancer mode when I have > > > CephFS kernel clients connected? Our cluster runs Squid and all > > > connected clients are on kernel 6.11-6.14, so they should be new > > > enough. However, they identify themselves as luminous (I could not > > > find clear documentation about this, but this seems to be hard-coded > > > and by design), so I cannot run ceph osd set-require-min-compat-client > > > reef, which is required for the balancer module to work. > > > > > > I have 500 clients connected and migrating them all to FUSE would be a > > > headache. Is there a way around that? Some of my pools have extremely > > > high read balance scores and we're also struggling with performance > > > issues as a result. > > > > > > Janek > > > > > > > > > _______________________________________________ > > > ceph-users mailing list -- [email protected] > > > To unsubscribe send an email to [email protected] > > > > -- > > Bauhaus-Universität Weimar > > Bauhausstr. 9a, R308 > > 99423 Weimar, Germany > > > > Phone: +49 3643 58 3577 > > www.webis.de > > > > _______________________________________________ > > ceph-users mailing list -- [email protected] > > To unsubscribe send an email to [email protected] > > > _______________________________________________ > ceph-users mailing list -- [email protected] > To unsubscribe send an email to [email protected] > _______________________________________________ ceph-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
