On Thu, Nov 19, 2015 at 06:35:24PM +0100, linux-btrfs.tebu...@xoxy.net wrote: > Many thanks to everybody on the list for the awful a lot help I received. > I'm impressed by the amount, quality and speed of the responses I received! > > See the FAQ[1] for how to interpret the output. ... > Very helpful, thanks. > > > The solution is to free up some of the data allocation, using a filtered > > balance. > As noted in my original post, this is already part of my "voodoo" I'm doing > in these situations.
Sometimes it's useful to know what the voodoo is actually doing. :) > Will newer kernel relieve me from this burden? Not in any current or planned kernel, to the best of my knowledge. > FYI: On executing "btrfs fi show" the first time after I deleted many > snapshots and did a filtered (-dusage) balance, it reported sth. like > devid 1 size 119.21GiB used 117.03GiB > now (after a unfiltered balance?) it reports > devid 1 size 119.21GiB used 66.06GiB > > I'm really confuzzled. It's just freed up lots of space. You'll probably find that your "total" value for data in btrfs fi df is close to (but not exactly) 66 GiB now, if you've just run a full unfiltered balance. (The difference being made up of metadata). > > [..] Ubuntu repeatedly chooses to stabilize on exactly the wrong kernel > > versions. > > .. > > Give http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1.13-wily/ a try. > Could not agree more. Will give wily kernel a try. > > > The output is really a little confusing. [..] should make the output more > > understandable. > +1 > Considering that the status of a file systems should be understandable by > regular users, it would be great if the btrfs tools could provide additional > user hints like _"I seems your metadata space is running out of space. Please > run `foo bar` to resolve this situation or consult FAQ[4] for more details"_. There's a repo of "useful btrfs scripts" that David Sterba looks after. I think there's already a script to go in your cron.daily directory that already does the check and balances if necessary. If there isn't, there should be (and it shouldn't be that hard to write, either). David -- where is that repo? [snip] > I'm still a bit puzzled how to avoid my situation in the first place. > Should I pick "btrfs show" in favor to "btrfs fi df" to learn about an > impending "disk full" situation? In the general case, you need both of them to make sense of it. (Or just btrfs fi usage) You're looking for the FS fully allocated, and metadata usage+block reserve very close to metadata allocation. > Will newer kernels do the balance on their own? I think it's on the "projects" list on the wiki, so it may get done eventually. As I said above, I'm not aware of anyone working on it. Hugo. -- Hugo Mills | 2 + 2 = 5, for sufficiently large values of 2. hugo@... carfax.org.uk | http://carfax.org.uk/ | PGP: E2AB1DE4 |
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