On Mon, Nov 25, 2013 at 5:58 AM, Mark Nelson <mark.nelson@xxxxxxxxxxx> wrote: > On 11/25/2013 07:21 AM, Shu, Xinxin wrote: >> >> Recently , I want to enable rbd cache to identify performance benefit. I >> add rbd_cache=true option in my ceph configure file, I use ’virsh >> attach-device’ to attach rbd to vm, below is my vdb xml file. > > > Ceph configuration files are a bit confusing because sometimes you'll see > something like "rbd_cache" listed somewhere but in the ceph.conf file you'll > want a space instead: > > rbd cache = true > > with no underscore. That should (hopefully) fix it for you! I believe the config file will take either format. The RBD cache is a client-side thing, though, so it's not ever going to show up in the OSD! You want to look at the admin socket created by QEMU (via librbd) to see if it's working. :) -Greg -Greg > >> >> <disk type='network' device='disk'> >> >> <driver name='qemu' type='raw' cache='writeback'/> >> >> <source protocol='rbd' >> >> name='rbd/node12_2:rbd_cache=true:rbd_cache_writethrough_until_flush=true'/> >> >> <target dev='vdb' bus='virtio'/> >> >> <serial>6b5ff6f4-9f8c-4fe0-84d6-9d795967c7dd</serial> >> >> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' >> function='0x0'/>i >> >> </disk> >> >> I do not know this is ok to enable rbd cache. I see perf counter for rbd >> cache in source code, but when I used admin daemon to check rbd cache >> statistics, >> >> Ceph –admin-daemon /var/run/ceph/ceph-osd.0.asok perf dump >> >> But I did not get any rbd cahce flags. >> >> My question is how to enable rbd cahce and check rbd cache perf counter, >> or how can I make sure rbd cache is enabled, any tips will be >> appreciated? Thanks in advanced. >> >> >> >> _______________________________________________ >> 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 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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