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>
# / was on /dev/sdb2 during installation
UUID=801945e5-0a98-4d53-baf3-1801d85b3a66 /               btrfs   defaults,subvol=@ 0       1
# /boot/efi was on /dev/sda2 during installation
UUID=B8D2-E11D  /boot/efi       vfat    umask=0077      0       1
# /home was on /dev/sdb2 during installation
UUID=801945e5-0a98-4d53-baf3-1801d85b3a66 /home           btrfs   defaults,subvol=@home 0       2
# swap was on /dev/sdb1 during installation
UUID=25ce838c-6473-487e-8417-000de481f829 none            swap    sw              0       0



sudo blkid /dev/sdb2 
/dev/sdb2: UUID="801945e5-0a98-4d53-baf3-1801d85b3a66" UUID_SUB="4a5c3a38-b0f7-4a66-abf8-76cd340b01dc" TYPE="btrfs" PARTUUID="3fc532e1-d953-44b0-8a9d-5c2a0a7b4b76"