On Fri, 20 May 2016 17:00:03 +0800 lin zhou wrote: > Hi,cephers > we only using krbd in ceph.and it works well near two yeas.but now I > face a size problem. > > I have 7 nodes with 10 3T osd each.we using ceph 0.67.9 in > ubuntu12.04.I know it is too old,but update is beyond my control. > > and now we use 80% size,so we start to delete historic unneeded > data,but free size do not increase. > > and then I found total assigned size of rbds are much bigger than > ceph size,so it means if we do not do something,it will reach the > limit. > > but the true data in the user side,we only use 40%. > > I read the blog of Sebastien and some maillist.I know the command of > fstrim in kernel 3.18 can deal with it. and is it risky that update > kernel to 3.18 in ubuntu12.04? > > I try to add discard option in mount command,but it do not work. > > so what way do you recommend to free krbd size in ceph 0.67.9 in > ubuntu12.04 > If you're considering a kernel upgrade (and thus a service interruption), another option would be to unmount that image on your old machine, mount it on a newer machine and/or with librbd and fuse and then run fstrim. However trim is a pretty costly activity in Ceph, so it may a) impact your cluster performance and b) take a while, depending on how much data we're talking about. Lastly, while having a sparse storage serice like Ceph is very nice I always try to have enough actual space available to handle all commitments. Christian -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Global OnLine Japan/Rakuten Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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