Change partition label in Ubuntu

To change partition label on various file systems use:

FAT16/32

mlabel -i /dev/sdb1 ::my_external

NTFS

ntfslabel /dev/sdb1 my_external

EXT3/4

e2label /dev/sdb1 my_external

BTRFS
For BTRFS you can set label while creating the partition with:
mkfs.btrfs –-label LABEL_LABEL

mkfs.btrfs –L LABEL_LABEL