May I also suggest the same for export/import mechanism? Say, if image was created by fallocate we may also want to leave holes upon upload and vice-versa for export. On Mon, Sep 9, 2013 at 8:45 AM, Sage Weil <sage@xxxxxxxxxxx> wrote: > On Sat, 7 Sep 2013, Oliver Daudey wrote: >> Hey all, >> >> This topic has been partly discussed here: >> http://lists.ceph.com/pipermail/ceph-users-ceph.com/2013-March/000799.html >> >> Tested on Ceph version 0.67.2. >> >> If you create a fresh empty image of, say, 100GB in size on RBD and then >> use "rbd cp" to make a copy of it, even though the image is sparse, the >> command will attempt to read every part of it and take far more time >> than expected. >> >> After reading the above thread, I understand why the copy of an >> essentially empty sparse image on RBD would take so long, but it doesn't >> explain why the copy won't be sparse itself. If I use "rbd cp" to copy >> an image, the copy will take it's full allocated size on disk, even if >> the original was empty. If I use the QEMU "qemu-img"-tool's >> "convert"-option to convert the original image to the copy without >> changing the format, essentially only making a copy, it takes it's time >> as well, but will be faster than "rbd cp" and the resulting copy will be >> sparse. >> >> Example-commands: >> rbd create --size 102400 test1 >> rbd cp test1 test2 >> qemu-img convert -p -f rbd -O rbd rbd:rbd/test1 rbd:rbd/test3 >> >> Shouldn't "rbd cp" at least have an option to attempt to sparsify the >> copy, or copy the sparse parts as sparse? Same goes for "rbd clone", >> BTW. > > Yep, this is in fact a bug. Opened http://tracker.ceph.com/issues/6257. > > Thanks! > sage > _______________________________________________ > 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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