ENOSPC during balance with filesystem switching read-only (system info)

ENOSPC during balance with filesystem switching read-only (system info)

[Sylvain Falardeau]

Hi again,

I just realized I did not add the system information:

Ubuntu 20.04

uname -a

Linux jbak100 5.13.0-28-generic #31~20.04.1-Ubuntu SMP Wed Jan 19 
14:08:10 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

(It was booted in version 5.4 from Ubuntu when I got the error and I 
tried using linux-image-generic-hwe-20.04 which correspond to 5.13.0-28 
above to see if it fixed the issue).

btrfs --version
btrfs-progs v5.4.1


Label: none  uuid: c56123f0-7b5f-46b2-b53a-60f2657e9bf1
         Total devices 6 FS bytes used 17.70TiB
         devid    2 size 7.28TiB used 7.23TiB path /dev/sdd1
         devid    3 size 7.28TiB used 7.28TiB path /dev/sde1
         devid    4 size 7.28TiB used 7.28TiB path /dev/sdf1
         devid    5 size 7.26TiB used 7.26TiB path /dev/sdb3
         devid    6 size 7.24TiB used 5.62TiB path /dev/sda4
         devid    7 size 14.55TiB used 793.51GiB path /dev/sdc1

btrfs fi df /srv/backups/
Data, RAID10: total=1.04TiB, used=1.04TiB
Data, RAID1: total=16.49TiB, used=16.49TiB
System, RAID1: total=32.00MiB, used=3.59MiB
Metadata, RAID10: total=80.00MiB, used=57.50MiB
Metadata, RAID1: total=195.00GiB, used=182.21GiB
GlobalReserve, single: total=512.00MiB, used=0.00B

The dmesg portion was included in my original message.

One interesting detail is devid 5 with `btrfs fi show` indicate a size 
of 7.26TiB but in `btrfs fi usage` is shows 7.26TiB unallocated. Is it 
normal?

Thank you.

-- 
Sylvain Falardeau