Hi,
Thank you, that make sense for testing, but i'm afraid not in my case.
Even i test on the volume that already test many times, the IOPS will not growing up
again. Yeah, i mean, this VM is broken, IOPS of the VM will never growing up..
Thanks!
hzwulibin@xxxxxxxxx
From: Chen, XiaoxiDate: 2015-11-02 14:11Subject: RE: [performance] why rbd_aio_write latency increase from 4ms to 7.3ms after the same testPre-allocated the volume by "DD" across the entire RBD before you do any performance test:).In this case, you may want to re-create the RBD, pre-allocate and try again.> -----Original Message-----> From: ceph-devel-owner@xxxxxxxxxxxxxxx [mailto:ceph-devel-> owner@xxxxxxxxxxxxxxx] On Behalf Of hzwulibin> Sent: Monday, November 2, 2015 1:24 PM> To: ceph-devel; ceph-users> Subject: [performance] why rbd_aio_write latency increase from 4ms to> 7.3ms after the same test>> Hi,> same environment, after a test script, the io latency(get from sudo ceph --> admin-daemon /run/ceph/guests/ceph-client.*.asok per dump) increase> from about 4ms to 7.3ms>> qemu version: debian 2.1.2> kernel:3.10.45-openstack-amd64> system: debian 7.8> ceph: 0.94.5> VM CPU number: 4 (cpu MHz : 2599.998)> VM memory size: 16GB> 9 OSD storage servers, with 4 SSD OSD on each, total 36 OSDs.>> Test scripts in VM:> # cat reproduce.sh> #!/bin/bash>> times=20> for((i=1;i<=$times;i++))> do> tmpdate=`date "+%F-%T"`> echo> "=======================$tmpdate($i/$times)===================> ===="> tmp=$((i%2))> if [[ $tmp -eq 0 ]];then> echo "############### fio /root/vdb.cfg ###############"> fio /root/vdb.cfg> else> echo "############### fio /root/vdc.cfg ###############"> fio /root/vdc.cfg> fi> done>>> tmpdate=`date "+%F-%T"`> echo "############### [$tmpdate] fio /root/vde.cfg ###############"> fio /root/vde.cfg>>> # cat vdb.cfg> [global]> rw=randwrite> direct=1> numjobs=64> ioengine=sync> bsrange=4k-4k> runtime=180> group_reporting>> [disk01]> filename=/dev/vdb>>> # cat vdc.cfg> [global]> rw=randwrite> direct=1> numjobs=64> ioengine=sync> bsrange=4k-4k> runtime=180> group_reporting>> [disk01]> filename=/dev/vdc>> # cat vdd.cfg> [global]> rw=randwrite> direct=1> numjobs=64> ioengine=sync> bsrange=4k-4k> runtime=180> group_reporting>> [disk01]> filename=/dev/vdd>> # cat vde.cfg> [global]> rw=randwrite> direct=1> numjobs=64> ioengine=sync> bsrange=4k-4k> runtime=180> group_reporting>> [disk01]> filename=/dev/vde>> After run the scripts reproduce.sh, the disks in the VM's IOPS cutdown from> 12k to 5k, the latency increase from 4ms to 7.3ms.>> run steps:> 1. create a VM> 2. create four volumes and attatch to the VM 3. sh reproduce.sh 4. in the> runtime of reproduce.sh, run "fio vdd.cfg" or "fio vde.cfg" to checkt the> performance>> After reproduce.sh finished, performance down.>>> Anyone has the same problem or has some ideas about this?>> Thanks!> --------------> hzwulibin> 2015-11-02> {.n + +% lzwm b 맲 r yǩ ׯzX ܨ} Ơz &j:+v zZ+ +zf h ~ i z w ?> & )ߢf
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