Re: space still allocated post deletion

[Graham Cobb <g.btrfs@cobb.uk.net>]

On 19/04/2022 11:41, Alex Powell wrote:
> Hi team,
> I have deleted hundreds of GB of files however space still remains the
> same, even after a full balance and a dusage=0 balance. The location I
> am deleting from is usually a mount point but I found some files had
> saved there while the array was unmounted, which I then removed.

Most likely you have files in subvolumes which are not currently mounted
anywhere. You need to mount the root subvolume of the filesystem to see
all the files. Many distros default to putting the system root into a
non-root subvolume.

I think you can see them all if you use:

btrfs subv list -a /

To access them...

mkdir /mnt/1
mount -o subvolid=5 /dev/sdh2 /mnt/1

Graham

> 
> root@bean:/home/bean# du -h --max-depth=1 /mnt/data/triage
> 6.4G /mnt/data/triage/complete
> 189G /mnt/data/triage/incomplete
> 195G /mnt/data/triage
> 
> root@bean:/home/bean# rm -rf /mnt/data/triage/complete/*
> root@bean:/home/bean# rm -rf /mnt/data/triage/incomplete/*
> root@bean:/home/bean# du -h --max-depth=1 /mnt/data/triage
> 0 /mnt/data/triage/complete
> 0 /mnt/data/triage/incomplete
> 0 /mnt/data/triage
> 
> root@bean:/home/bean# btrfs filesystem show
> Label: none  uuid: 24933208-0a7a-42ff-90d8-f0fc2028dec9
> Total devices 1 FS bytes used 209.03GiB
> devid    1 size 223.07GiB used 211.03GiB path /dev/sdh2
> 
> root@bean:/home/bean# du -h --max-depth=1 /
> 244M /boot
> 91M /home
> 7.5M /etc
> 0 /media
> 0 /dev
> 0 /mnt
> 0 /opt
> 0 /proc
> 2.7G /root
> 1.6M /run
> 0 /srv
> 0 /sys
> 0 /tmp
> 3.6G /usr
> 13G /var
> 710M /snap
> 22G /
> 
> Linux bean 5.15.0-25-generic #25-Ubuntu SMP Wed Mar 30 15:54:22 UTC
> 2022 x86_64 x86_64 x86_64 GNU/Linux
> btrfs-progs v5.16.2