Hi Greg, Am 17.09.2015 um 16:42 schrieb Gregory Farnum: > Briefly, if you do a lot of small direct IOs (for instance, a database > journal) then striping lets you send each sequential write to a > separate object. This means they don't pile up behind each other > grabbing write locks and can complete in parallel. Striping them > instead of just having small block-sized objects means the objects are > still of a reasonable size for RADOS. >
Sounds good - why not enabled it always/ by default? Is the only drawback that there's no support by kernel rbd? What's the recommended stripe size for "normal" qemu workloads? 64k? > I *think* that's just because the features are only filled in if > they're in use (the kernel doesn't/didn't support striping, despite > supporting other V2 image features) and required to understand the > image, but maybe I'm misunderstanding you or forgetting how the RBD > team set things up. That doesn't seem to be the case. When I use librbd direcly (for example using ceph-ruby) the feature is immediately visible, just as all other features. Thanks! Corin _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
