Re: RBD performance - tuning hints

[Josh Durgin <josh.durgin@inktank.com>]

On 08/29/2012 01:50 AM, Alexandre DERUMIER wrote:
> Nice results !
> (can you make same benchmark from a qemu-kvm guest with virtio-driver ?
> I have made some bench some month ago with stephan priebe, and we never be able to have more than 20000iops, with a full ssd 3nodes cluster)
>
>>> How can I set the variables when the Journal data have go to the OSD ? (after X seconds and/or when Y %-full)
> I think you can try to tune these values
>
> filestore max sync interval = 30
> filestore min sync interval = 29
> filestore flusher = false
> filestore queue max ops = 10000

Increasing filestore_op_threads might help as well.

> ----- Mail original -----
>
> De: "Dieter Kasper" <d.kasper@kabelmail.de>
> À: ceph-devel@vger.kernel.org
> Cc: "Dieter Kasper (KD)" <d.kasper@kabelmail.de>
> Envoyé: Mardi 28 Août 2012 19:48:42
> Objet: RBD performance - tuning hints
>
> Hi,
>
> on my 4-node system (SSD + 10GbE, see bench-config.txt for details)
> I can observe a pretty nice rados bench performance
> (see bench-rados.txt for details):
>
> Bandwidth (MB/sec): 961.710
> Max bandwidth (MB/sec): 1040
> Min bandwidth (MB/sec): 772
>
>
> Also the bandwidth performance generated with
> fio --filename=/dev/rbd1 --direct=1 --rw=$io --bs=$bs --size=2G --iodepth=$threads --ioengine=libaio --runtime=60 --group_reporting --name=file1 --output=fio_${io}_${bs}_${threads}
>
> .... is acceptable, e.g.
> fio_write_4m_16 795 MB/s
> fio_randwrite_8m_128 717 MB/s
> fio_randwrite_8m_16 714 MB/s
> fio_randwrite_2m_32 692 MB/s
>
>
> But, the write IOPS seems to be limited around 19k ...
> RBD 4M 64k (= optimal_io_size)
> fio_randread_512_128 53286 55925
> fio_randread_4k_128 51110 44382
> fio_randread_8k_128 30854 29938
> fio_randwrite_512_128 18888 2386
> fio_randwrite_512_64 18844 2582
> fio_randwrite_8k_64 17350 2445
> (...)
> fio_read_4k_128 10073 53151
> fio_read_4k_64 9500 39757
> fio_read_4k_32 9220 23650
> (...)
> fio_read_4k_16 9122 14322
> fio_write_4k_128 2190 14306
> fio_read_8k_32 706 13894
> fio_write_4k_64 2197 12297
> fio_write_8k_64 3563 11705
> fio_write_8k_128 3444 11219
>
>
> Any hints for tuning the IOPS (read and/or write) would be appreciated.
>
> How can I set the variables when the Journal data have go to the OSD ? (after X seconds and/or when Y %-full)
>
>
> Kind Regards,
> -Dieter
>
>
>

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