There is TRIM/discard support and I use it with some success. There are some details here http://ceph.com/docs/master/rbd/qemu-rbd/ The one caveat I have is that I've sometimes been able to crash an osd by doing fstrim inside a guest. On Aug 22, 2013, at 10:24 AM, Guido Winkelmann <guido-ceph@xxxxxxxxxxxxxxxxx> wrote: > Hi, > > RBD has had support for sparse allocation for some time now. However, when > using an RBD volume as a virtual disk for a virtual machine, the RBD volume > will inevitably grow until it reaches its actual nominal size, even if the > filesystem in the guest machine never reaches full utilization. > > Is there some way to reverse this? Like going through the whole image, looking > for large consecutive areas of zeroes and just deleting the objects for that > area? How about support for TRIM/discard commands used by some modern > filesystems? > > Guido > _______________________________________________ > 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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