On 2025/06/22 23:19, Anthony D'Atri wrote: > >> I don't have enough RAM for 4GB per OSD. > > DIMMs are cheap.
No DIMMs on Apple Macs. > You might experiment with the values described here: > > docs.ceph.com <https://docs.ceph.com/en/latest/rados/configuration/ > bluestore-config-ref/> > > <https://docs.ceph.com/en/latest/rados/configuration/bluestore-config-ref/> > > <https://docs.ceph.com/en/latest/rados/configuration/bluestore-config-ref/> > > > Eg bluestore_cache_size_* > >> Nonetheless, this behavior is clearly broken. > > You’re welcome to submit a PR. Make no mistake, you’re actively > disregarding recommendations with unrealistic recommendations. To submit a PR I first need to figure out what's going on, hence my email. "This is not recommended and performance may suffer" is one thing, "the cache will thrash to death" is another. I don't expect this setup to have ideal performance, but I do expect it not to have completely broken cache behavior, which is what is happening. > >> I also confirmed that `ceph tell osd.X cache drop` also >> fixes the CPU usage (until the cache fills up again). If something is >> assuming the cache is at least 4GB when sizing partitions or something >> like that, then I'd like to know how to tune it (and the default should >> probably be improved to remove that assumption). > > See above. Please submit a PR that behaves the way you want, with > empirical evidence that it does not adversely impact the wide variety of > deployments that follow recommendations. Given how averse you seem to be to even consider improving this use case and dismissive of my report, I'm not particularly inclined to submit a PR at this point. If one of the tunables fixes this for me, I'll just keep the fix to myself and the next person to run into it will have to figure it out for themselves again. *shrug* - Hector _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
