Re: 800 GByte free, but "no space left"

[Hugo Mills <hugo-lkml@carfax.org.uk>]

[-- Attachment #1: Type: text/plain, Size: 2109 bytes --]

On Mon, Dec 06, 2010 at 01:42:00PM +0100, Helmut Hullen wrote:
> Hallo, Hugo,
> 
> Du meintest am 06.12.10:
> 
> >>> After running "balance" it looks better:
> 
> >>> Label: 'MM2'  uuid: ad7c0668-316c-4a79-ba00-3b505b9d99b4
> >>> 	Total devices 2 FS bytes used 2.39TB
> >>> 	devid    2 size 1.35TB used 1.20TB path /dev/sdc3
> >>> 	devid    1 size 1.81TB used 1.20TB path /dev/sdf2
> >>
> >> And now:
> >>
> >> Filesystem           1K-blocks      Used Available Use% Mounted on
> >> /dev/sdc3            3400799848 2569770888 831028960  76% /srv/MM
> >>
> >> But after copying about 300 MByte (part of a 1.5-GByte *.mpg) I got
> >> "no space left on device". Looks like balancing has stolen about 300
> >> GByte.
> 
> >    This sounds exactly like a problem I've had. What output do you
> > get from "btrfs fi df /srv/MM"?
> 
> I've just written a script for gathering the (perhaps) interesting data  
> ...
> 
> # btrfs filesystem show
> Label: 'MM2'  uuid: ad7c0668-316c-4a79-ba00-3b505b9d99b4
> 	Total devices 2 FS bytes used 2.37TB
> 	devid    2 size 1.35TB used 1.20TB path /dev/sdc3
> 	devid    1 size 1.81TB used 1.20TB path /dev/sdf2
> 
> Btrfs Btrfs v0.19
> 
> # btrfs filesystem df /srv/MM
> Data: total=2.39TB, used=2.37TB
> Metadata: total=5.25GB, used=3.51GB
> System: total=12.00MB, used=188.00KB

   Can you try that again with either the latest 2.6.37-rc, or with
the btrfs-unstable kernel? There's a bug in earlier versions that
breaks the reporting of RAID types, which is what I wanted to see
here.

> I've moved about 50 Gbyte away from "srv/MM" in the meantime, before  
> running the script with this output.
> 
> And I don't dare running "balance" again - maybe it reduces the  
> available space again and again.

   If you've hit the bug I think you have, then yes, it will.

   Hugo.

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
  PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
  --- Do not meddle in the affairs of wizards, for they are subtle, ---  
                           and quick to anger.                           

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 190 bytes --]