Btrfs Snapshots

Part of CachyOS Wiki Notes. From the official CachyOS wiki (last updated 2026-07-06).

Snapshots are not backups. A snapshot is a read-only or read-write (default) copy of a subvolume at a point in time, space-efficient because it references the original data until something changes. It lives on the same disk, so it dies with the disk.

• CachyOS default subvolumes: /, /root, /home, /var/cache, /var/tmp, /var/log, /srv.
• Good for: recovery from breakage or corruption after updates, a misconfig that prevents boot, accidental deletion.
• Not useful for: bootloader problems, hardware failure.
• CachyOS ships snap-pac by default, so Snapper automatically creates snapshots before and after every pacman install, upgrade or removal.
• Guidance: keep roughly 10 snapshots max, use them for recovery, and give each a meaningful description.

GUI — Btrfs Assistant

Requires btrfsmaintenance.

btrfs-assistant-launcher

sudo -E btrfs-assistant

Retention settings (root config selected): Hourly/Daily/Weekly/Monthly/Yearly = 0; untick Enable timeline snapshots; Number = 10; tick Snapper cleanup enabled; Save + Apply systemd changes → enables snapper-cleanup.timer.

Verify in /etc/snapper/configs/root; expected:

# limit for number cleanup
NUMBER_MIN_AGE="3600"
NUMBER_LIMIT="10"
NUMBER_LIMIT_IMPORTANT="10"

Delete snapshots with Btrfs Assistant’s Delete button, then regenerate bootloader entries (systemd-boot / GRUB / Limine — see Boot Manager Configuration).

CLI — Snapper

Snapper comes from openSUSE and is the underlying tool. CachyOS’s default Snapper config only covers the root subvolume (/) — other subvolumes need their own configs.

# Show the current configuration
sudo snapper get-config
 
# List snapshots and details
sudo snapper list
 
# Create a snapshot
sudo snapper create --type single --description "My Snapshot Description"
 
# Modify a snapshot
sudo snapper modify <option> <snapshot_number>
sudo snapper modify 729 --description 'My New Snapshot Description'
 
# Delete one snapshot
sudo snapper delete <snapshot_number>
 
# Delete a range
sudo snapper delete 718-721

modify options: --description/-d, --cleanup-algorithm/-c, --userdata/-u, --read-only, --read-write, --default.

snapper list columns: # (snapshot number, used by other commands), Type (single = standalone, pre = before a system change, post = after, linked to a pre snapshot), Pre # (the paired pre snapshot), Date, User, Cleanup (algorithm: number, timeline, or empty-pre-post), Description, Userdata.

Snapshot 0 cannot be deleted — it represents the current state of the filesystem.

Limine snapshot menu limit — back up first, then edit:

sudo cp /etc/limine-snapper-sync.conf /etc/limine-snapper-sync.conf.orig
sudo nano /etc/limine-snapper-sync.conf

Set MAX_SNAPSHOT_ENTRIES=10; SNAPSHOT_FORMAT_CHOICE=8 is recommended (date, time, description).

Gotcha: if a snapshot involved a kernel update, you cannot roll back to it.

GRUB users need the scripts/hooks that add snapshots to the menu:

sudo pacman -Syu grub-btrfs-support

Docs: snapper.io/manpages/snapper.html, snapper.io/manpages/snapper-configs.html, Arch Wiki Snapper.

Related: CachyOS Filesystems, CachyOS Boot Managers, Boot Manager Configuration.