Re: Where is the disk space?

[Marc MERLIN <marc@merlins.org>]

On Fri, Nov 13, 2015 at 07:45:21PM +0000, Duncan wrote:
> Marc MERLIN posted on Fri, 13 Nov 2015 09:41:01 -0800 as excerpted:
> 
> > Any ideas?
> 
> Without addressing the main question, a couple targets of opportunity:
> 
> 1) A quick balance with -mprofiles=single should kill those unused single 
> metadata and system mkfs.btrfs legacies so you don't have to see them in 
> fi df.
> 
> 2) While fi df reports the data total vs. used spread being close enough 
> that it's unsurprising a balance -dusage=80 didn't give you anything 
> back, the spread on metadata is rather higher, dup, 6.0 gig total, less 
> than 1 gig used, so a balance -musage=50 or 80 should return a few gigs, 
> 4-5 I'd guess, leaving you 1-2 gig metadata total.

Well, -musage helped, I didn't know about that one, thanks:
root@polgara:/mnt/btrfs_root# btrfs fi show .
Label: 'btrfs_root'  uuid: a2a1ed7b-6bfe-4e83-bc10-727126ed17bf
        Total devices 1 FS bytes used 39.09GiB
        devid    1 size 55.88GiB used 51.88GiB path /dev/sdb5

btrfs-progs v4.0-dirty
root@polgara:/mnt/btrfs_root# btrfs balance start -musage=80 -v /mnt/btrfs_root
Dumping filters: flags 0x6, state 0x0, force is off
  METADATA (flags 0x2): balancing, usage=80
  SYSTEM (flags 0x2): balancing, usage=80
Done, had to relocate 14 out of 55 chunks
root@polgara:/mnt/btrfs_root# btrfs fi show .
Label: 'btrfs_root'  uuid: a2a1ed7b-6bfe-4e83-bc10-727126ed17bf
        Total devices 1 FS bytes used 39.75GiB
        devid    1 size 55.88GiB used 41.91GiB path /dev/sdb5

btrfs-progs v4.0-dirty
root@polgara:/mnt/btrfs_root# df -h .
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdb5        56G   41G   15G  74% /mnt/btrfs_root

I'm still seeing 39GB used for 28GB of actual data, but I definitely
fixed one bit already thanks to you.

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
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Home page: http://marc.merlins.org/                         | PGP 1024R/763BE901