The btrfs device command is a command-line utility in Linux that is used to manage devices and disks in a btrfs file system. btrfs device is a utility that is included in the btrfs-progs package, which is a collection of tools and libraries for managing btrfs file systems.
Btrfs is a copy-on-write (CoW) file system that is included in the Linux kernel and is known for its advanced features and capabilities, such as snapshotting, incremental backups, and more. btrfs device is a tool that allows you to add, remove, or modify the devices and disks that are used by a btrfs file system.
To use btrfs device, you will need to have the btrfs-progs package installed on your Linux system. btrfs-progs is usually available as a package in the repositories of popular Linux distributions, and you can install it using the package manager for your specific distribution.
btrfs device Command Examples
1. Add one or more devices to a btrfs filesystem:
# btrfs device add /path/to/block_device1 /path/to/block_device2 /path/to/btrfs_filesystem
2. Remove a device from a btrfs filesystem:
# btrfs device remove /path/to/device|device_id [...]
3. Display error statistics:
# btrfs device stats /path/to/btrfs_filesystem
4. Scan all disks and inform the kernel of all detected btrfs filesystems:
# btrfs device scan --all-devices
5. Display detailed per-disk allocation statistics:
# btrfs device usage /path/to/btrfs_filesystem