>>when i switch the journal to the OSD Disk seperate partiton on each disk >>(/dev/sdX1 for journal 1GB and /dev/sdX2 for OSD) i go down from 23.000 >>iops to 200 iops random 4k. O_o , that's seem crazy... Are you sure that your partitions are correctly aligned ? (starting first partition at sector 2048 is best for ssd) ----- Mail original ----- De: "Stefan Priebe - Profihost AG" <s.priebe@xxxxxxxxxxxx> À: "Sébastien Han" <han.sebastien@xxxxxxxxx> Cc: "Mark Nelson" <mark.nelson@xxxxxxxxxxx>, "Alexandre DERUMIER" <aderumier@xxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>, "Mark Kampe" <mark.kampe@xxxxxxxxxxx> Envoyé: Vendredi 23 Novembre 2012 11:31:15 Objet: Re: RBD fio Performance concerns Hi, when i switch the journal to the OSD Disk seperate partiton on each disk (/dev/sdX1 for journal 1GB and /dev/sdX2 for OSD) i go down from 23.000 iops to 200 iops random 4k. Greets, Stefan Am 22.11.2012 13:50, schrieb Sébastien Han: >> journal is running on tmpfs to me but that changes nothing. > > I don't think it works then. According to the doc: Enables using > libaio for asynchronous writes to the journal. Requires journal dio > set to true. > > > On Thu, Nov 22, 2012 at 12:48 PM, Stefan Priebe - Profihost AG > <s.priebe@xxxxxxxxxxxx> wrote: >> Am 22.11.2012 11:49, schrieb Sébastien Han: >> >>> @Alexandre: cool! >>> >>> @ Stefan: Full SSD cluster and 10G switches? >> >> Yes >> >> >>> Couple of weeks ago I saw >>> that you use journal aio, did you notice performance improvement with it? >> >> journal is running on tmpfs to me but that changes nothing. >> >> Stefan > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
