HI Igor, but the performance issue is still present even on the recreated OSD. # ceph tell osd.38 bench -f plain 12288000 4096 bench: wrote 12 MiB in blocks of 4 KiB in 1.63389 sec at 7.2 MiB/sec 1.84k IOPS vs. # ceph tell osd.10 bench -f plain 12288000 4096 bench: wrote 12 MiB in blocks of 4 KiB in 10.7454 sec at 1.1 MiB/sec 279 IOPS both baked by the same SAMSUNG SSD as block.db. Greets, Stefan Am 28.04.20 um 19:12 schrieb Stefan Priebe - Profihost AG:
Hi Igore, Am 27.04.20 um 15:03 schrieb Igor Fedotov:
Just left a comment at https://tracker.ceph.com/issues/44509
Generally bdev-new-db performs no migration, RocksDB might eventually do that but no guarantee it moves everything.
One should use bluefs-bdev-migrate to do actual migration.
And I think that's the root cause for the above ticket.
perfect - this removed all spillover in seconds.
Greets, Stefan
Thanks,
Igor
On 4/24/2020 2:37 PM, Stefan Priebe - Profihost AG wrote:
No not a standalone Wal I wanted to ask whether bdev-new-db migrated dB and Wal from hdd to ssd.
Stefan
Am 24.04.2020 um 13:01 schrieb Igor Fedotov <ifedotov@suse.de>:
Unless you have 3 different types of disks beyond OSD (e.g. HDD, SSD, NVMe) standalone WAL makes no sense.
On 4/24/2020 1:58 PM, Stefan Priebe - Profihost AG wrote:
Is Wal device missing? Do I need to run *bluefs-bdev-new-db and Wal?*
Greets, Stefan
Am 24.04.2020 um 11:32 schrieb Stefan Priebe - Profihost AG <s.priebe@profihost.ag>:
Hi Igor,
there must be a difference. I purged osd.0 and recreated it.
Now it gives: ceph tell osd.0 bench { "bytes_written": 1073741824, "blocksize": 4194304, "elapsed_sec": 8.1554735639999993, "bytes_per_sec": 131659040.46819863, "iops": 31.389961354303033 }
What's wrong wiht adding a block.db device later?
Stefan
Am 23.04.20 um 20:34 schrieb Stefan Priebe - Profihost AG: > Hi, > if the OSDs are idle the difference is even more worse: > # ceph tell osd.0 bench > { > "bytes_written": 1073741824, > "blocksize": 4194304, > "elapsed_sec": 15.396707875000001, > "bytes_per_sec": 69738403.346825853, > "iops": 16.626931034761871 > } > # ceph tell osd.38 bench > { > "bytes_written": 1073741824, > "blocksize": 4194304, > "elapsed_sec": 6.8903985170000004, > "bytes_per_sec": 155831599.77624846, > "iops": 37.153148597776521 > } > Stefan > Am 23.04.20 um 14:39 schrieb Stefan Priebe - Profihost AG: >> Hi, >> Am 23.04.20 um 14:06 schrieb Igor Fedotov: >>> I don't recall any additional tuning to be applied to new DB >>> volume. And assume the hardware is pretty the same... >>> >>> Do you still have any significant amount of data spilled over >>> for these updated OSDs? If not I don't have any valid >>> explanation for the phenomena. >> >> just the 64k from here: >> https://tracker.ceph.com/issues/44509 >> >>> You might want to try "ceph osd bench" to compare OSDs under >>> pretty the same load. Any difference observed >> >> Servers are the same HW. OSD Bench is: >> # ceph tell osd.0 bench >> { >> "bytes_written": 1073741824, >> "blocksize": 4194304, >> "elapsed_sec": 16.091414781000001, >> "bytes_per_sec": 66727620.822242722, >> "iops": 15.909104543266945 >> } >> >> # ceph tell osd.36 bench >> { >> "bytes_written": 1073741824, >> "blocksize": 4194304, >> "elapsed_sec": 10.023828538, >> "bytes_per_sec": 107118933.6419194, >> "iops": 25.539143953780986 >> } >> >> >> OSD 0 is a Toshiba MG07SCA12TA SAS 12G >> OSD 36 is a Seagate ST12000NM0008-2H SATA 6G >> >> SSDs are all the same like the rest of the HW. But both drives >> should give the same performance from their specs. The only other >> difference is that OSD 36 was directly created with the block.db >> device (Nautilus 14.2.7) and OSD 0 (14.2.8) does not. >> >> Stefan >> >>> >>> On 4/23/2020 8:35 AM, Stefan Priebe - Profihost AG wrote: >>>> Hello, >>>> >>>> is there anything else needed beside running: >>>> ceph-bluestore-tool --path /var/lib/ceph/osd/ceph-${OSD} >>>> bluefs-bdev-new-db --dev-target /dev/vgroup/lvdb-1 >>>> >>>> I did so some weeks ago and currently i'm seeing that all osds >>>> originally deployed with --block-db show 10-20% I/O waits while >>>> all those got converted using ceph-bluestore-tool show 80-100% >>>> I/O waits. >>>> >>>> Also is there some tuning available to use more of the SSD? The >>>> SSD (block-db) is only saturated at 0-2%. >>>> >>>> Greets, >>>> Stefan >>>> _______________________________________________ >>>> ceph-users mailing list -- ceph-users@ceph.io >>>> To unsubscribe send an email to ceph-users-leave@ceph.io