Have you ever accidentally deleted a folder and lost important data? Or an OS upgrade broke your system and you were forced to reinstall it? Or one of your partitions got full while others still had free space?

When you install a Linux distro, it is not always obvious how much space /home or /root will need in the future. If you choose the wrong size, you have to resize partitions later, which is annoying.

Btrfs solves these problems. With Btrfs, you format your whole drive as a single partition (and a small EFI partition for UEFI). You organize your data in subvolumes. You don’t choose a fixed size for each subvolume - they just take as much space as they need from the drive.

Creating a subvolume is simple: btrfs subvolume create /path/to/subvol

You mount them like regular partitions:

mount /dev/$DISK -o subvol=/path/to/subvol /mount/path

Btrfs also lets you backup data easily with snapshots:

btrfs subvolume snapshot -r /path/to/subvol /path/to/new/snapshot

Initially, these snapshots only copy the metadata, not the actual data. After snapshotting a 100GB subvolume, you might only use ~1KB of extra space. The metadata keeps “pointers” to the blocks of your files. When you update a big file that exists in multiple subvolumes, only the updated blocks get duplicated. This results in very small space usage increase.

If your system breaks, you can replace the broken subvolume with a snapshot of the last working state. You don’t even need a live-USB if you keep a small rescue system - just snapshot your initial system after install and make it bootable. Some tools even allow automated snapshots of the base system and let you boot directly into them.

Another option is ZFS, which is very powerful. It is less common on Linux because of license issues, so it requires more manual work to setup. In fact, Btrfs was created as a result of those licensing issues to give Linux a native filesystem with similar features.

This is how I organize my system with Btrfs.