On Fri, Mar 20, 2020 at 2:23 PM <vitalif@xxxxxxxxxx> wrote: > > > Anything with an iodepth of 1 is going to be (relatively) terrible on > > RBD. > > iodepth=128 results in 300 iops in the same setup. Not much better :) > > > The forthcoming Octopus release of librbd adds support for sparse > > copy-up writes [1] when your min OSD release is set to Octopus (reads > > from the parent image were already sparse-read ops). Using holes was > > previously not very practical due to the large allocations sizes on > > the OSD, but with the change to 4KiB minimum block sizes, such a > > technique would be possible (albeit a breaking change for all older > > clients controlled via a new feature bit). You also have the ability > > to control the RBD object sizes and use something smaller than the > > 4MiB default. > > That's good news! Is it already in 15.1.1, can I test it? Yup, but you need 15.1.z OSDs as well as 15.1.z librbd. Also ensure you run "ceph osd require-osd-release octopus" otherwise it won't use the new sparse-copyup since older OSDs don't have the necessary support. > -- > Vitaliy Filippov > -- Jason _______________________________________________ Dev mailing list -- dev@xxxxxxx To unsubscribe send an email to dev-leave@xxxxxxx
