PikaOS4 BTRFS Subvolumes

# I created paritions manually with the tool available through the installer
# This is the overview of them (though after I did the actual install to see also where it mounted what)
pikaos@pikaos:~$ lsblk -o name,size,fstype,label,mountpoint,UUID
NAME     SIZE FSTYPE   LABEL       MOUNTPOINT                                UUID
loop0      3G squashfs             /usr/lib/live/mount/rootfs/filesystem.squ
sda      240G
├─sda1   100M vfat     WINDOWS EFI /boot/efi                                 F765-E8AC
├─sda2    60G ntfs     Windows                                               0F92C14A06C486F3
├─sda3   500M vfat     LINUX_EFI   /media/pikaos/installation/boot/efi       F762-00A9
├─sda4  1000M ext4     PikaOS      /media/pikaos/installation/boot           209aacb7-cfe9-4b41-8429-ca6976a41f8e
└─sda5 178.4G btrfs                /media/pikaos/installation                d1655934-1d5e-4378-aeaa-b7be50fc0d6b
sr0      3.2G iso9660  PikaOS 4    /usr/lib/live/mount/medium                2024-11-05-10-16-20-00
zram0    256M                      [SWAP]

# create subvolumes
sudo mkdir /mnt
sudo mount -o subvolid=5 /dev/sda5 /mnt
sudo btrfs subvolume create /mnt/@d
sudo btrfs subvolume create /mnt/@home
sudo btrfs sub create /mnt/@cache
sudo btrfs sub create /mnt/@log
sudo btrfs sub create /mnt/@tmp

pikaos@pikaos:~$ sudo btrfs subvolume list /mnt
ID 256 gen 8 top level 5 path @
ID 257 gen 8 top level 5 path @home
ID 258 gen 9 top level 5 path @tmp
ID 259 gen 9 top level 5 path @log
ID 260 gen 9 top level 5 path @cache

# here I installed Pika OS 4
# I just selected sda3 as EFI, sda4 as Boot and sda5 as root parition
# And continued with the installation

# It went fine but the installer did not seem to detect the subvolumes:
pikaos@pikaos:~$ cat /mnt/etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# /dev/sda5
UUID=d1655934-1d5e-4378-aeaa-b7be50fc0d6b       /               btrfs           rw,relatime,ssd,discard=async,space_cache=v2,subvol=/    0 0

# /dev/sda4 LABEL=PikaOS
UUID=209aacb7-cfe9-4b41-8429-ca6976a41f8e       /boot           ext4            rw,relatime     0 2

# /dev/sda3 LABEL=LINUX_EFI
UUID=F762-00A9          /boot/efi       vfat            rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro    0 2

# /dev/sda4 LABEL=PikaOS
UUID=209aacb7-cfe9-4b41-8429-ca6976a41f8e       /boot           ext4            rw,relatime     0 2

# /dev/sda3 LABEL=LINUX_EFI
UUID=F762-00A9          /boot/efi       vfat            rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro    0 2