https://www.thegeekdiary.com/btrfs-command-examples-to-create-and-manage-btrfs-file-system/
https://mpdesouza.com/blog/new-btrfs-feature-delete-subvolumes-using-subvolume-ids/
https://docs.oracle.com/cd/E37670_01/E37355/html/ol_delsnp_btrfs.html



sudo btrfs subvolume list /;
sudo btrfs subvolume list / -apt;

sudo btrfs subvolume show /;
sudo btrfs subvolume show /home;

sudo btrfs filesystem show;
sudo btrfs filesystem label /home;
sudo btrfs filesystem df /root;
sudo btrfs filesystem df /home;
sudo btrfs filesystem df /Data;

sudo systemctl list-units --type=mount --all;

df -h /;
df -h /Data;


# -  - #
# - Create grub.cfg file - #
sudo btrfs qgroup show /;
sudo btrfs qgroup show /home;



df -ht btrfs;
sudo btrfs filesystem df /;
sudo btrfs filesystem show /;
btrfs device usage /;
btrfs filesystem df /;
btrfs filesystem df /home;


sudo btrfs filesystem sync
sudo btrfs filesystem defragment
sudo btrfs filesystem resize

sudo btrfs filesystem label

sudo btrfs filesystem show;
sudo btrfs filesystem sync /home/Data; 


btrfs scrub Utilities

sudo btrfs scrub start;
sudo btrfs scrub cancel;
sudo btrfs scrub resume;
sudo btrfs scrub status;


sudo btrfs scrub start /home/Data;
sudo btrfs scrub status –dR /home/Data;


sudo btrfs subvolume list .;
sudo btrfs subvolume list /Data;

btrfs subvolume create /btrfs/SV1;
btrfs subvolume snapshot /btrfs/SV1 /btrfs/SV1-snap

btrfs subvolume snapshot –r /btrfs/SV1 /btrfs/SV1-rosnap 
Create a readonly snapshot of ‘/btrfs/SV1’ in ‘/btrfs/SV1-rosnap’

btrfs device add /dev/sdd /btrfs
sudo btrfs filesystem balance /;  # After adding a device



sudo btrfs subvolume delete /@badroot
mount -o subvolid=0 /dev/some-device /mnt
sudo btrfs subvolume list /home


# -  - #
# - Delete all subvolumes under /home - #
#sudo ls /home | xargs btrfs subvolume delete;





# -  - #
# - Show mounted subvolumes - #
findmnt -nt btrfs;
findmnt -nt btrfs --output TARGET;
mount | grep btrfs;
sudo btrfs filesystem show;
sudo btrfs filesystem show | awk '/ path /{print $NF}'



sudo btrfs subvolume list .;
sudo btrfs subvolume snapshot / /snap/root

usage: btrfs subvolume snapshot [-r] <source> <dest>|[<dest>/]<name>

    btrfs subvolume snapshot [-r] [-i <qgroupid>] <source> <dest>|[<dest>/]<name>

    Create a snapshot of the subvolume
    Create a writable/readonly snapshot of the subvolume <source> with
    the name <name> in the <dest> directory.  If only <dest> is given,
    the subvolume will be named the basename of <source>.

    -r             create a readonly snapshot
    -i <qgroupid>  add the newly created snapshot to a qgroup. This
                   option can be given multiple times.





sudo btrfs check --force /dev/vda4;
sudo btrfs filesystem show;
sudo btrfs filesystem show | awk '/ path /{print $NF}';
sudo btrfs filesystem show | grep devid;





https://www.christitus.com/btrfs-guide


Create Snapshot

sudo btrfs subvolume snapshop /home /home/.snapshots/2020-01-13

Using this you can revert the snapshop by simply editing the /etc/fstab and 
changing the subvol=2020-01-13 or the corresponding subvolid 
you get from sudo btrfs subv list /home

Restore Snapshot
Restore Snapshop after reboot and successful rollback

sudo btrfs subvolume delete /home
sudo btrfs subvolume snapshot /home/.snapshots/2020-01-13 /home





https://kaisenlinux.org/documentation/advanced-btrfs-utilisation.html