> >> [osd] >> bluestore_cache_autotune = 0 > > Why are you turning autotuning off?
FWIW I’ve encountered the below assertions. I neither support nor deny them, pasting here for discussion. One might interpret this to only apply to OSDs with DB on a seperate (faster) device. >>> With random small block workloads, it’s important to keep BlueStore >>> metadata cached and keep RocksDB from spilling over to slow media – >>> including during compaction. If there is adequate memory on the OSD node, >>> it is recommended to increase the BlueStore metadata cache ratio. An >>> example of this is shown below: >>> >>> bluestore_cache_meta_ratio = 0.8 >>> bluestore_cache_kv_ratio = 0.2 >>> osd bluestore_cache_size_ssd 6GB >>> >>> In Ceph Nautilus and above, the cache ratios are automatically tuned so it >>> is recommended to first observe the relevant cache hit counters in >>> BlueStore before manually setting these parameters. There is some >>> disagreement regarding how effective the auto tuning is. >>> >>>> https://ceph.io/community/bluestore-default-vs-tuned-performance-comparison/ >>>> suggests that we still set >>>> >>>> bluestore_cache_size_ssd = 8GB with 12GB memory target. _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
