Hugo Mills posted on Tue, 02 Sep 2014 13:13:49 +0100 as excerpted: > On Tue, Sep 02, 2014 at 12:05:33PM +0000, Holger Hoffstätte wrote: >> >> I updated to progs-3.16 and noticed during testing: >> root>mkfs.btrfs -f /dev/loop0 >> All fine until here.. >> >> root>btrfs filesystem df /tmp/btrfs >> Data, single: total=8.00MiB, used=64.00KiB >> System, DUP: total=8.00MiB, used=16.00KiB >> System, single: total=4.00MiB, used=0.00 >> Metadata, DUP: total=409.56MiB, used=112.00KiB >> Metadata, single: total=8.00MiB, used=0.00 > > Note that the "single" chunks are empty, and will remain so. > >> So where does the confusing initial display come from? [I] don't >> remember ever seeing this with btrfs-progs-3.14.2. > > Your memory is faulty, I'm afraid. It's always done that -- at > least since I started using btrfs, several years ago. > > I believe it comes from mkfs creating a trivial basic filesystem > (with the single profiles), and then setting enough flags on it that the > kernel can bootstrap it with the desired chunks in it -- but I may be > wrong about that. Agreed. It's an artifact of the mkfs.btrfs process and a btrfs fi df on a new filesystem always seems to have those extra unused single profile lines. I got so the first thing I'd do on first mount was a balance -- before there was anything actually on the filesystem so it was real fast -- to get rid of those null entries. Actually, I had already created a little mkfs.btrfs helper script that sets options I normally want, etc, and after doing the mkfs and balance drill a few times, I setup the script such that if at the appropriate prompt I give it a mountpoint to point balance at, it'll mount the filesystem and immediately run a balance, thus automating things and making the balance part of the same scripted process that does the mkfs.btrfs in the first place. IOW, those null-entry lines bother me too... enough that even tho I know what they are I arranged things so they're automatically and immediately eliminated and I don't have to see 'em! =:^) -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
