so correcly aligned... Maybe try to use journal directly on the full partition, without xfs ? ----- Mail original ----- De: "Stefan Priebe - Profihost AG" <s.priebe@xxxxxxxxxxxx> À: "Alexandre DERUMIER" <aderumier@xxxxxxxxx> Cc: "Mark Nelson" <mark.nelson@xxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>, "Mark Kampe" <mark.kampe@xxxxxxxxxxx>, "Sébastien Han" <han.sebastien@xxxxxxxxx> Envoyé: Vendredi 23 Novembre 2012 11:49:10 Objet: Re: RBD fio Performance concerns Am 23.11.2012 11:47, schrieb Alexandre DERUMIER: >>> 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) Model: ATA INTEL SSDSC2CW24 (scsi) Disk /dev/sdb: 468862128s Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 2048s 2342911s 2340864s xfs pri 2 2342912s 468860927s 466518016s xfs pri 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