User:Chrismurphy/lvm2btrfs

Commands

LVM commands	Btrfs commands	Note
pvs,pvdisplay	btrfs filesystem show	shows all btrfs, mounted or not
vgs,vgdisplay	btrfs device usage /mnt	device allocation info
	btrfs filesystem usage /mnt	most complete command
lvs	btrfs subvolume list	not exact analogs
lvdisplay	btrfs subvolume show	not exact analogs
pvcreate+vgextend+lvresize+resize2fs/xfs_growfs+(fsadm resize)	btrfs device add /dev/ /mnt	mkfs and resize are implied
(fsadm resize)+resize2fs/xfs_growfs+lvresize+vgreduce+pvcreate	btrfs device remove /dev/ /mnt	data migration, resize, magic wipe are implied
resize2fs/xfs_growfs	btrfs filesystem resize
pvmove	btrfs replace; or	preferred; new drive must be equal to or larger than old
	btrfs device add; then btrfs device remove	mkfs and resize are implied data migration, resize, magic wipe are implied
lvcreate	btrfs subvolume create
lvcreate --snapshot	btrfs subvolume snapshot -r	lvm snapshots are initially ro, btrfs snapshots are rw unless -r is used
lvremove	btrfs subvolume delete
?	btrfs filesystem du	btrfs specific du, shows total, shared, and exclusive usage for a subvolume or directory; only comes into play with snapshotting and reflinks, otherwise it'll match regular du
?	btrfs scrub start/status/cancel/resume	online metadata/data integrity check, only csum verification, is not an fsck

FAQ

Why do 'du' and 'btrfs filesystem du' totals differ?

Most likely due to inline extents. du will compute small files with a minimum 4KiB, the data block size. But the actual storage consumption of small files when inline (saved with the inode metadata in a leaf, hence inline) is quite a bit less.