Hi, I don't use mds, but I thinks it's the same like with rdb - the readed data are cached on the OSD-nodes. The 4MB-chunks of the 3G-file fit completly in the cache, the other not. Udo On 18.01.2017 07:50, Ahmed Khuraidah wrote: > Hello community, > > I need your help to understand a little bit more about current MDS > architecture. > I have created one node CephFS deployment and tried to test it by fio. > I have used two file sizes of 3G and 320G. My question is why I have > around 1k+ IOps when perform random reading from 3G file into > comparison to expected ~100 IOps from 320G. Could somebody clarify > where is read buffer/caching performs here and how to control it? > > A little bit about setup - Ubuntu 14.04 server that consists Jewel > based: one MON, one MDS (default parameters, except mds_log = false) > and OSD using SATA drive (XFS) for placing data and SSD drive for > journaling. No RAID controller and no pool tiering used > > 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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