On Thu, 2013-01-24 at 19:56 -0700, Chris Murphy wrote: > On Jan 24, 2013, at 5:44 PM, Adam Williamson <awill...@redhat.com> > wrote: > > > > Just about everything in btrfs is really different :) I'm still > wrapping > > my head around it too. But as far as possible, the 'legacy' tools > should > > show something as accurate and useful as they can, I believe. > > For mount, the only issue I know of is that it doesn't show subvolume > mounted. Ubuntu reportedly does (I don't use it so I can't > confirm/deny), even though it's using older btrfs-progs, and older > linux-utils. So I'm not sure why Fedora doesn't show subvolumes in > mount. I have to do cat /proc/self/mountinfo to get this information > on Fedora. > > For df, it's maybe more challenging. The use cases where it's a > problem: small devices, e.g. less than 100GB and also not formatted > with the mixed data/metadata option; and pushing the usage of a device > of any size to nearly it's full capacity (beyond 90%). But even a > scale algorithm that changes the Capacity % bias from predominantly > data, to predominantly metadata doesn't fix the problem. > > e.g. 95% Capacity per df, with a heavy metadata usage of the file > system. Further metadata heavy writes might mean you're actually at > 99% Capacity, whereas with minimal metadata writes might mean you're > at 92% capacity. So which is correct to report? It depends on future > usage, which is unknown. Small problem.
Well that's not the one I was thinking of, actually - I believe I was hit by cases where some subvols use redundancy, in which case df goes completely wrong. I'd have to re-install and re-check to be sure of exactly what I saw go wrong, though. -- Adam Williamson Fedora QA Community Monkey IRC: adamw | Twitter: AdamW_Fedora | identi.ca: adamwfedora http://www.happyassassin.net -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel
