Progress update:
- tweaked debug_rocksdb to 1/5. *possibly* helped, fewer slow requests
- will increase osd_memory_target from 4 to 16G, and observe
On 24/06/20 1:30 pm, Mark Kirkwood wrote:
> Hi,
>
> We have recently added a new storage node to our Luminous (12.2.13)
> cluster. The prev nodes are all setup as Filestore: e.g 12 osds on hdd
> (Seagate Constellations) with one NVMe (Intel P4600) journal. With the
> new guy we decided to introduce Bluestore so it is configured as:
> (same HW) 12 osd with data on hdd and db + wal on one NVMe.
>
> We noticed there are periodic slow requests logged, and the implicated
> osds are the Bluestore ones 98% of the time! This suggests that we
> need to tweak our Bluestore settings in some way. Investigating I'm
> seeing:
>
> - A great deal of rocksdb debug info in the logs - perhaps we should
> tone that down? (debug_rocksdb 4/5 -> 1/5)
>
> - We look to have the default cache settings
> (bluestore_cache_size_hdd|ssd etc), we have memory to increase these
>
> - There are some buffered io settings (bluefs_buffered_io,
> bluestore_default_buffered_write), set to (default) false. Are these
> safe (or useful) to change?
>
> - We have default rocksdb options, should some of these be changed?
> (bluestore_rocksdb_options, in particular max_background_compactions=2
> - should we have less, or more?)
>
> Also, anything else we should be looking at?
>
> regards
>
> Mark
>
> _______________________________________________
> ceph-users mailing list -- ceph-users(a)ceph.io
> To unsubscribe send an email to ceph-users-leave(a)ceph.io