On Tue, May 30, 2023 at 8:42 AM Ben <ruidong.gao@xxxxxxxxx> wrote: > > Hi, > > We are performing couple performance tests on CephFS using fio. fio is run > in k8s pod and 3 pods will be up running mounting the same pvc to CephFS > volume. Here is command line for random read: > fio -direct=1 -iodepth=128 -rw=randread -ioengine=libaio -bs=4k -size=1G > -numjobs=5 -runtime=500 -group_reporting -directory=/tmp/cache > -name=Rand_Read_Testing_$BUILD_TIMESTAMP > The random read is performed very slow. Here is the cluster log from > dashboard: > [...] > Any suggestions on the problem? Your random read workload is too extreme for your cluster of OSDs. It's causing slow metadata ops for the MDS. To resolve this we would normally suggest allocating a set of OSDs on SSDs for use by the CephFS metadata pool to isolate the worklaods. -- Patrick Donnelly, Ph.D. He / Him / His Red Hat Partner Engineer IBM, Inc. GPG: 19F28A586F808C2402351B93C3301A3E258DD79D _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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