It's not a zero-cost operation since it involves librbd issuing 1 to N delete or truncate ops to the OSDs. The OSD will treat those ops just like any other read or write op (i.e. they don't take lower priority). Additionally, any discard smaller than the stripe period of the RBD image will potentially result in "write-zero" operations if the extent happens to be in the middle of a backing object. On Wed, May 9, 2018 at 10:25 AM, Andre Goree <andre@xxxxxxxxxx> wrote: > Is there anything I should be concerned with performance-wise when having my > libvirt-based guest systems run trim on their attached RBD devices? I'd > imagine it all happens in the background (on the Ceph cluster) with minimal > performance hit, given the fact that normal removal/deletion of files > usually consists in an asynchronous operation, but I thought I'd ask to be > sure. > > -- > Andre Goree > -=-=-=-=-=- > Email - andre at drenet.net > Website - http://blog.drenet.net > PGP key - http://www.drenet.net/pubkey.html > -=-=-=-=-=- > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Jason _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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