Greate, thanks. Is it safe to change it manually in ceph.conf until next nautilus release or should I wait for the next nautilus release for this change? I mean does qa run on this value for this config that we could trust and change it or should we wait until the next nautilus release that qa ran on this value? On Thu, Aug 20, 2020 at 5:25 PM Igor Fedotov <ifedotov@xxxxxxx> wrote: > Hi Seena, > > this parameter isn't intended to be adjusted in production environments - > it's supposed that default behavior covers all regular customers' needs. > > The issue though is that default setting is invalid. It should be > 'use_some_extra'. Gonna fix that shortly... > > > Thanks, > > Igor > > > > > On 8/20/2020 1:44 PM, Seena Fallah wrote: > > Hi Igor. > > Could you please tell why this config is in LEVEL_DEV ( > https://github.com/ceph/ceph/pull/29687/files#diff-3d7a065928b2852c228ffe669d7633bbR4587)? > As it is documented in Ceph we can't use LEVEL_DEV in production > environments! > > Thanks > > On Thu, Aug 20, 2020 at 1:58 PM Igor Fedotov <ifedotov@xxxxxxx> wrote: > >> Hi Simon, >> >> >> starting Nautlus v14.2.10 Bluestore is able to use 'wasted' space at DB >> volume. >> >> see this PR: https://github.com/ceph/ceph/pull/29687 >> >> Nice overview on the overall BlueFS/RocksDB design can be find here: >> >> >> https://cf2.cloudferro.com:8080/swift/v1/AUTH_5e376cddf8a94f9294259b5f48d7b2cd/ceph/rocksdb_in_ceph.pdf >> >> Which also includes some overview (as well as additional concerns) for >> changes brought by the above-mentioned PR. >> >> >> Thanks, >> >> Igor >> >> >> On 8/20/2020 11:39 AM, Simon Oosthoek wrote: >> > Hi Michael, >> > >> > thanks for the explanation! So if I understand correctly, we waste 93 >> > GB per OSD on unused NVME space, because only 30GB is actually used...? >> > >> > And to improve the space for rocksdb, we need to plan for 300GB per >> > rocksdb partition in order to benefit from this advantage.... >> > >> > Reducing the number of small files is something we always ask of our >> > users, but reality is what it is ;-) >> > >> > I'll have to look into how I can get an informative view on these >> > metrics... It's pretty overwhelming the amount of information coming >> > out of the ceph cluster, even when you look only superficially... >> > >> > Cheers, >> > >> > /Simon >> > >> > On 20/08/2020 10:16, Michael Bisig wrote: >> >> Hi Simon >> >> >> >> As far as I know, RocksDB only uses "leveled" space on the NVME >> >> partition. The values are set to be 300MB, 3GB, 30GB and 300GB. Every >> >> DB space above such a limit will automatically end up on slow devices. >> >> In your setup where you have 123GB per OSD that means you only use >> >> 30GB of fast device. The DB which spills over this limit will be >> >> offloaded to the HDD and accordingly, it slows down requests and >> >> compactions. >> >> >> >> You can proof what your OSD currently consumes with: >> >> ceph daemon osd.X perf dump >> >> >> >> Informative values are `db_total_bytes`, `db_used_bytes` and >> >> `slow_used_bytes`. This changes regularly because of the ongoing >> >> compactions but Prometheus mgr module exports these values such that >> >> you can track it. >> >> >> >> Small files generally leads to bigger RocksDB, especially when you >> >> use EC, but this depends on the actual amount and file sizes. >> >> >> >> I hope this helps. >> >> Regards, >> >> Michael >> >> >> >> On 20.08.20, 09:10, "Simon Oosthoek" <s.oosthoek@xxxxxxxxxxxxx> >> wrote: >> >> >> >> Hi >> >> >> >> Recently our ceph cluster (nautilus) is experiencing bluefs >> >> spillovers, >> >> just 2 osd's and I disabled the warning for these osds. >> >> (ceph config set osd.125 bluestore_warn_on_bluefs_spillover false) >> >> >> >> I'm wondering what causes this and how this can be prevented. >> >> >> >> As I understand it the rocksdb for the OSD needs to store more >> >> than fits >> >> on the NVME logical volume (123G for 12T OSD). A way to fix it >> >> could be >> >> to increase the logical volume on the nvme (if there was space >> >> on the >> >> nvme, which there isn't at the moment). >> >> >> >> This is the current size of the cluster and how much is free: >> >> >> >> [root@cephmon1 ~]# ceph df >> >> RAW STORAGE: >> >> CLASS SIZE AVAIL USED RAW USED >> >> %RAW USED >> >> hdd 1.8 PiB 842 TiB 974 TiB 974 >> >> TiB 53.63 >> >> TOTAL 1.8 PiB 842 TiB 974 TiB 974 >> >> TiB 53.63 >> >> >> >> POOLS: >> >> POOL ID STORED OBJECTS USED >> >> %USED MAX AVAIL >> >> cephfs_data 1 572 MiB 121.26M 2.4 GiB >> >> 0 167 TiB >> >> cephfs_metadata 2 56 GiB 5.15M 57 GiB >> >> 0 167 TiB >> >> cephfs_data_3copy 8 201 GiB 51.68k 602 GiB >> >> 0.09 222 TiB >> >> cephfs_data_ec83 13 643 TiB 279.75M 953 TiB >> >> 58.86 485 TiB >> >> rbd 14 21 GiB 5.66k 64 GiB >> >> 0 222 TiB >> >> .rgw.root 15 1.2 KiB 4 1 MiB >> >> 0 167 TiB >> >> default.rgw.control 16 0 B 8 0 B >> >> 0 167 TiB >> >> default.rgw.meta 17 765 B 4 1 MiB >> >> 0 167 TiB >> >> default.rgw.log 18 0 B 207 0 B >> >> 0 167 TiB >> >> cephfs_data_ec57 20 433 MiB 230 1.2 GiB >> >> 0 278 TiB >> >> >> >> The amount used can still grow a bit before we need to add >> >> nodes, but >> >> apparently we are running into the limits of our rocskdb >> >> partitions. >> >> >> >> Did we choose a parameter (e.g. minimal object size) too small, >> >> so we >> >> have too much objects on these spillover OSDs? Or is it that too >> >> many >> >> small files are stored on the cephfs filesystems? >> >> >> >> When we expand the cluster, we can choose larger nvme devices to >> >> allow >> >> larger rocksdb partitions, but is that the right way to deal >> >> with this, >> >> or should we adjust some parameters on the cluster that will >> >> reduce the >> >> rocksdb size? >> >> >> >> Cheers >> >> >> >> /Simon >> >> _______________________________________________ >> >> 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 >> _______________________________________________ >> 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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