On Wed, Sep 03, 2014 at 04:53:39AM +0000, Duncan wrote:
> 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:
> >> 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.

   Interesting. Last time I tried that (balance without any contents),
the balance removed *all* the chunks, and then the FS forgot about
what configuration it should have and reverted to RAID-1/single. I
usually recommend writing at least one 4k+ file to the FS first, if
it's bothering someone so much that they can't let it go.

   Hugo.

> 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! =:^)
> 

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
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