Apsis

Apsis takes snapshots of your system and can put it back to one of them. It is made for the COSMIC desktop: an applet in the panel shows when the last snapshot was taken and how full the backup disk is, and a window creates, lists, deletes and restores snapshots.

Snapshots are taken with rsync and hard-links, in Timeshift's layout on the backup disk. Common files are shared between snapshots, so each one looks complete but costs only the changes, and each is a plain folder you can browse with a file manager. Snapshots made by Timeshift keep working in Apsis, and Timeshift is not needed.

Apsis protects system files and settings. Your home folder is left out unless you include it, so restoring the system does not touch your documents.

Features

It lives in the panel

• The applet's tooltip shows the last snapshot and the backup disk; an optional label beside the icon shows both at a glance.
• The icon turns the warning colour when the last snapshot is older than you chose, or the disk is nearly full.
• Click it to see how full the backup disk is and how old the last snapshot is. Open Apsis opens the window.

Snapshots when you want them

• Create takes a snapshot, with a comment if you like. The first one copies the whole system; later ones copy only what changed. rsync runs at idle priority, so the desktop stays responsive.
• Delete removes one or several snapshots. Nothing is created or deleted on a schedule.
• Stop ends a snapshot while it is being made; what it copied so far is removed.
• Creating, deleting and saving settings touch system files, so your system asks for your password (polkit). The window itself never runs as root.
• Shortcuts: Ctrl+N create, Delete delete, Ctrl+R or F5 refresh, Ctrl+, settings, Ctrl+A select all, Esc close.

Where snapshots go

• Settings → Location lists the disks that can hold snapshots; the others are listed with the reason. An external disk is best: a snapshot on the system disk won't help if that disk dies.
• If Timeshift was set up before, Apsis offers its disk and filters; Save keeps them.

What is included

• The system is always included. /root and /home are tick boxes.
• Filters leave out (-) or keep (+) folders, files or patterns, as in Timeshift.
• With /home included, a restore can put your documents back as they were in the snapshot, or keep them as they are now.

The settings in detail: docs/SETTINGS.md.

Restore the system

• Select a snapshot and click Restore. Apsis checks that the snapshot fits this computer, takes a safety snapshot of the system as it is now, and asks you to restart.
• The restore runs at the next start with the desktop stopped, so no file is in use while it is replaced. Then the computer starts normally and the status line says how it went.
• The safety snapshot is the way back: restore it like any other snapshot.
• Restore is experimental. Read Known limitations of restore before you rely on it. The full guide: docs/RESTORE.md.

Supported systems

• Desktop: COSMIC, on Pop!_OS 24.04 or any distribution shipping it. rsync and a polkit agent (COSMIC has one).
• System disk: plain, or encrypted the way Pop!_OS's installer does it with "Encrypt drive" (an LVM volume inside one LUKS partition). Restore supports both.
• Backup disk: a plain, unencrypted Linux filesystem (ext4, btrfs, xfs...). The backup disk cannot be LUKS-encrypted; the system disk can.
• Restore: UEFI with systemd-boot (kernelstub), as on Pop!_OS 24.04. GRUB, BIOS boot, btrfs and a system split over /boot, /usr or /var partitions are refused before anything happens.

Install

From the .deb (Pop!_OS / Ubuntu 24.04 or newer, amd64): download apsis_<version>_amd64.deb from the releases page and install it from the folder you downloaded it to:

sudo apt install ./apsis_*.deb

From source (needs the build requirements under Contribute):

git clone https://github.com/atraxsrc/apsis
cd apsis
just                 # build (release)
sudo just install    # the applet, its launcher entry, and apsis-helper

Then add the applet: COSMIC Settings → Desktop → Panel → Configure panel applets, add Apsis. Or open Apsis from the app launcher.

Upgrading is the same apt install with the new file. While a snapshot, a delete or a restore's preparation runs, apt waits its turn and says so; run it again when the job has finished. Coming from 0.3 or 0.4: docs/TROUBLESHOOTING.md.

Uninstall

sudo apt remove apsis      # installed from the .deb (apt purge also removes /etc/apsis and /var/lib/apsis)
sudo just uninstall        # installed from source, run in the source folder

Your snapshots stay on the backup disk.

Known limitations of restore

• Experimental, for Pop!_OS 24.04 with systemd-boot only. Restore is new: a report of how it went on your hardware, good or bad, helps.
• An encrypted system disk works in Pop!_OS's "Encrypt drive" layout only. Its passphrase is asked twice: at the restart that runs the restore, and at the start after it.
• The live /etc/fstab and /etc/crypttab are kept, not the snapshot's. The boot files are refreshed with kernelstub; if that fails or the result fails the check, the computer keeps the boot files and the kernel it started with.
• A snapshot made while Apsis 0.5.x was installed puts 0.5.x back.
• Hard links are not kept in snapshots (as in Timeshift), and a file changed in place with the same size and time as in the snapshot is not restored.

The full list, and how Apsis's restore differs from Timeshift's: docs/RESTORE.md.

If a restore goes wrong

Don't keep restarting. Boot Pop!_OS Recovery (hold Space at power-on) or a live USB and follow docs/RECOVERY.md. Every time Apsis prepares a restore it writes the exact commands for this computer to timeshift/apsis-restore-RECOVER.txt on the backup disk. Keep that page where you can read it without this computer.

Troubleshooting

you see	what to do
Backup disk not connected	plug it in; Apsis notices and lists again
the list fails with a mount error that says the disk is already mounted	the desktop opened the backup disk by itself: unmount it in Files (unmount, don't eject), then Refresh
the applet doesn't show after installing	log out and back in, or re-add it in Configure panel applets
anything else	journalctl -u apsis-helper -e, and docs/TROUBLESHOOTING.md

Bugs and questions: open an issue. Say which version (the window's About page shows it), what you did and what the status line or the dialog said. Logs hold disk UUIDs, your user name and your computer's name: take out what you don't want public. A security problem doesn't go in an issue: report it privately as SECURITY.md describes.

Contribute

• Build requirements: Rust (stable), just and libcosmic's build dependencies. On Pop!_OS / Ubuntu / Debian:

  sudo apt install cargo just pkgconf libexpat1-dev libfontconfig-dev libfreetype-dev \
    libxkbcommon-dev libwayland-dev

• just run runs Apsis in a window, no root needed. Before a pull request, run what CI runs: cargo fmt --all --check, cargo clippy --locked --workspace --all-targets -- -D warnings and cargo test --locked --workspace.
• A report of how Restore went on your hardware, good or bad, is especially useful.
• The window's texts are in i18n/en/apsis.ftl. English is the only language so far.
• Bug reports, ideas, pull requests and security reports: CONTRIBUTING.md.

Name

In orbital mechanics an apsis is a turning point on an orbit, the point a body comes back to. The logo is an orbit with its two apsides, the glowing one being the point you return to.

License

GPL-3.0-only. See LICENSE.