On Thu, Mar 09, 2017 at 09:14:53AM +0200, Henrik Korkuc wrote: > On 17-03-09 05:38, Max Yehorov wrote: > >I was reading through release notes for 10.2.6 and there was a ticket > > > >rbd: rbd-nbd: disallow mapping images >2TB in size (issue#17219, > >pr#11870, Mykola Golub) > > > >default nbd block size is 1k, valid values are from 512 to PAGE_SIZE > > > >rbd_nbd.cc sets blocksize to 512 here: > >https://github.com/ceph/ceph/blob/master/src/tools/rbd_nbd/rbd-nbd.cc#L635 > > > >Why 512 was chosen for rbd_nbd? > >krbd also uses 512 sector size. Is there a reason to use 512 block > >size vs 4k AF? > I am also interested in >2TB NBD support and was disapointed when I couldn't > mount 10TB images. > > Based on issue in that commit for me it seems to be clear why it was done - > some (most?) kernels in the wild do not support larger sizes. But it looks > like support on unaffected kernels is already in master (not sure if it got > backported to current releases). For reference: > http://tracker.ceph.com/issues/17219 -> > https://github.com/ceph/ceph/pull/11741 -> > http://tracker.ceph.com/issues/18335 -> > https://github.com/ceph/ceph/pull/13229 Yes, it removes the restriction for working kernels. It is going to be backported to kraken and jewel: http://tracker.ceph.com/issues/18910 http://tracker.ceph.com/issues/18911 -- Mykola Golub -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
