You may want to set "ioengine=rbd", I guess. Cheers, ----- Original Message ----- From: "min fang" <louisfang2013@xxxxxxxxx> To: "ceph-users" <ceph-users@xxxxxxxxxxxxxx> Sent: Tuesday, March 1, 2016 1:28:54 PM Subject: rbd cache did not help improve performance Hi, I set the following parameters in ceph.conf [client] rbd cache=true rbd cache size= 25769803776 rbd readahead disable after byte=0 map a rbd image to a rbd device then run fio testing on 4k read as the command ./fio -filename=/dev/rbd4 -direct=1 -iodepth 64 -thread -rw=read -ioengine=aio -bs=4K -size=500G -numjobs=32 -runtime=300 -group_reporting -name=mytest2 Compared the result with setting rbd cache=false and enable cache model, I did not see performance improved by librbd cache. Is my setting not right, or it is true that ceph librbd cache will not have benefit on 4k seq read? thanks. _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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