Thanks Jason, thanks Dan, On 9 March 2016 at 01:34, Jason Dillaman <dillaman@xxxxxxxxxx> wrote: > Are you interesting in the max FD count or max thread count? You mention both in your email. True, I did mix the two somewhat incorrectly - I was sort of guessing there'd be some number of threads per socket or vice versa. I really should have made the subject "file/socket requirements for librbd", because in practice it's the FDs that we actually care about as both RedHat and Ubuntu default max_files soft ulimit seems to be quite low compared to all others. What still gripes me is that qemu doesn't seem to handle the error at all gracefully, i.e., not even an error logged - but perhaps that is actually up to librbd and could indicate a bug there? > Right now qemu doesn't pool OSD connections when you have multiple RBD images connected to the same VM -- each image uses its own librbd/librados instance. Since each image, at the worst case, might have to connect to each OSD and MON, that should be enough to determine the rough upper bound that you will require for qemu (e.g. 3 MONs, 1000 OSDs, max 10 RBD images per VM == roughly 10,000 socket connections worse case). Great, that's the sort of rough formula I was after - thank-you! -- Cheers, ~Blairo _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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