(Snap) LXD Resize default BTRFS storage pool

Hi @stgraber, thanks for your help.

Should I do the ‘btrfs filesystem resize’ on my container?
If not, on which loop device then?
This is on my host-server:

/dev/loop0                     55M   55M     0 100% /snap/lxd/8393
/dev/loop2                     88M   88M     0 100% /snap/core/5328
/dev/loop3                     87M   87M     0 100% /snap/core/4917
/dev/loop4                     87M   87M     0 100% /snap/core/5145
/dev/loop5                     55M   55M     0 100% /snap/lxd/8415
/dev/loop1                     55M   55M     0 100% /snap/lxd/8339

Thank you!

EDIT:

# lsblk -o NAME,FSTYPE,SIZE,MOUNTPOINT,LABEL
NAME                   FSTYPE       SIZE MOUNTPOINT      LABEL
loop0                  squashfs    54.6M /snap/lxd/8393  
loop1                  squashfs    54.6M /snap/lxd/8339  
loop2                  squashfs    87.9M /snap/core/5328 
loop3                  squashfs    86.9M /snap/core/4917 
loop4                  squashfs      87M /snap/core/5145 
loop5                  squashfs    54.6M /snap/lxd/8415  
loop6                  btrfs         10G                 default
sda                                  30G                 
|-sda1                 ext2         243M /boot           
`-sda2                 LVM2_member 29.8G                 
  |-noc--01--vg-root   ext4        27.8G /               
  `-noc--01--vg-swap_1 swap           2G [SWAP]          
sr0                                1024M    

# btrfs filesystem resize max /dev/loop6
ERROR: resize works on mounted filesystems and accepts only
directories as argument. Passing file containing a btrfs image
would resize the underlying filesystem instead of the image.