Trindle

Ways back when something goes wrong

Three things stand behind everything else: a snapshot taken around every software change, a backup of your apps and settings that you can carry to another computer, and a disk you can encrypt.

Before and afterA snapshot around every install, update and removal
From the boot menuStart from an old snapshot even when the computer will not start
One fileYour apps, their data and your settings, carried to another computer
A line of snapshots: one before a change, one after it, and another before the next change.BeforeUpdateAfterBeforea software changerestoring puts the system back to a marked point
Every install, update and removal sits between two snapshots.

Snapshots

When the system is on Btrfs, a snapshot of it is taken before and after every software change: installing, updating or removing anything from Debian or a software source. The work is done by snapper, the same tool other Linux systems use for this.

Settings, Snapshots lists them all. The camera button takes one now, which is what you want before trying something you may wish to undo.

Your files are not in them. When Trindle was put on with the Trindle Installer, your home folder has a part of the disk of its own and is left out of the snapshots, so restoring never touches your documents. Settings, Snapshots says so plainly if this computer is laid out differently. The home folder has snapshots of its own, switched on from the first start: one a day, kept for a week unless you choose another time, so an older version of a file can be had back from Folders.

Putting one back

  1. Open Settings and choose Snapshots.Every snapshot is listed with what was happening when it was taken.
  2. Press the restore arrow beside the one from before things went wrong.It asks a second time to be sure.
  3. Restart.The system is as it was then. What it was a moment ago is set aside, not deleted, so you can change your mind.
Settings, Snapshots: a list of five snapshots to go back to, each with a restore arrow and a bin

Settings, Snapshots. Every snapshot listed, with what was happening when it was taken.

The boot menu, listing Trindle, Trindle snapshots, advanced options and another operating system.Choose what to startTrindleTrindle snapshotsAdvanced optionsWindows Boot Manager
Other systems on the disk keep their place in the boot menu, and the snapshots have an entry of their own.

If the computer will not start

Hold Esc as the computer starts to bring up the boot menu, which stays out of sight when Trindle is the only system on the disk. Choose Trindle snapshots, then a snapshot. It starts as it was then, with a writable layer held in memory: nothing you do there is kept, so you can look round safely. If it is the one you want, restore it in Settings and it becomes the real system.

Other systems on the disk keep their own entries in the same menu, so a computer that dual boots still boots both.

Or drop to text. Ctrl, Alt and F2 gives an ordinary text login if the login screen itself fails. Ctrl, Alt and F7 goes back.
Apps on its Move your apps page: switches for what to take, a button to make the backup, and a place to choose a backup file to put back

Move your apps sits in Apps' own list, under Software sources.

Take your desktop with you

In Apps, choose Move your apps. Switch on what to take: your apps, their own data, your AppImages and Trindle's settings. One backup file is made in your home folder. Copy it to a USB stick or to cloud storage.

On the other computer, open the same page, press Choose a backup file and pick the file. The apps are installed fresh from Flathub, and their data and your settings are put back. Log out and back in to see every setting.

Trindle Flat makes the same kind of file, ending in .fmpack, so it can open a Trindle backup, and a backup or app list made by Flat can be chosen here.

What goes in

  • The list of your Flatpak apps
  • Those apps' own settings and data
  • Your AppImages
  • Trindle's own settings

What does not

  • Your documents, pictures and other files
  • Wi-Fi passwords
  • Your GitHub key

Copy those over yourself. Apps already on the other computer keep their own settings; only the apps it installs get theirs back.

Why an update need not strand you

Three kinds of update, each done in its own place, and each with a way back.

Apps you installed

Open Apps and choose Updates, then press the update button. Flatpak apps are installed for you alone, so a broken app is yours to remove and cannot stop the computer starting.

Debian itself

Apps, then Updates: one button fetches Debian’s own updates and installs them. A snapshot is taken around it, so an update that breaks something can be put back. Debian’s security fixes go in by themselves every day unless you switch off Check for updates in Settings, About this computer. No terminal, and nothing to type.

Trindle

Trindle comes from its own update source, apt.trindle.org, on the same Updates page as everything else: one button, with a snapshot around it. Some updates ask for a restart, and the page says when.

Kept through all of it. Your settings, your apps and your files are in your own home folder, which updates to Debian and Trindle do not touch.

Trindle is built on Debian stable, which is 13 at the time of writing, and comes as a whole operating system.

The Snapshots list: five snapshots, each with the day and time, what was happening, a restore arrow and a bin
Settings, Snapshots: one taken before and one after each change, a camera to take one now, and a restore arrow beside each.

The two ways to unlock it

A passwordYou type it each time the computer starts, before anything else appears. Nothing but that password opens the disk, and nothing else needs to be trusted.
This computer's chipThe TPM chip opens the disk, so nothing is typed at start-up and the computer goes straight to the login screen. The password you chose is still your way back in if the board is replaced or the chip refuses.
NeitherYou can leave the disk unlocked. Anyone who takes the drive out can read everything on it.

The installer can suggest a passphrase if you would rather not invent one. No password is ever refused: a bar shows how strong the one you typed is and roughly how long a computer would take to guess it. It is asked for twice, so a typo cannot lock you out.

A disk nobody else can read

The Trindle Installer offers to encrypt the part of the disk Trindle goes on, where the system and your files live, using LUKS, the standard Linux way of doing it. An encrypted disk cannot be read by anyone who takes it out of this computer.

This is the one choice that cannot be changed afterwards without installing again, so it is worth a moment on the installer's Privacy page rather than pressing Next.

Lose the password and the disk is gone. There is no spare key and nobody can recover it for you. Write it down and keep it somewhere safe.
The same disk twice: unlocked in this computer its files are there as you left them, locked or taken out its contents are unreadable. This disk Unlocked, in this computer Your files, as you left them Locked, or taken out Nothing on it can be read 7b 2f a9 0c e4 51 d8 36 bb 9a 04 7e c3 18 6d f21c 88 5d f0 23 ae 6b 94 c7 12 3f d1 08 5a e7 30 9ca4 09 6e b2 57 cc 31 8f 0d 75 e9 22 4b d6 10 875e d3 47 1b 90 fa 2c 68 b5 03 8e c6 71 24 df 39 0bc2 7a 05 96 6f b8 41 0e da 53 27 e5 9b 14 68 f338 e1 5c 0a 84 d9 26 7d b3 4f 11 c8 60 a2 75 ef 09
In this computer it is your disk as usual. Out of it, there is nothing on it anybody can read.

The smaller safeguards

Things put in because they were needed, not because they made a list look longer.

A screen change undoes itself

Change the screen size and Settings asks you to press Keep. Do nothing for fifteen seconds and it goes back, so a wrong choice never leaves you staring at nothing.

The system disk is guarded

Drives can erase a USB stick or another drive, and asks twice. For the disk the computer runs on it offers one change only: making room for a new partition, on Btrfs, after a snapshot.

Changes that need root go through one helper

Settings and Apps ask trindle-admin, through pkexec. It checks every argument it is given and reads passwords from standard input only.

The clipboard forgets

A password copied from a password manager is never kept in the history, and the clipboard is emptied 30 seconds later. The rest of the history clears itself on the schedule you chose.

A record of each session

Kept in .local/state/trindle/session.log in your home folder, which is what to look at when something went wrong.

No account, no telemetry

No account and nothing that tracks you. The update checks happen by themselves, and one switch in Settings, About this computer, turns them off. Everything the computer sends is listed on the privacy page.

Ready to put it on a computer?

What you need, writing the image to a USB stick, and every question the Trindle Installer asks.

How to install it
Use at your own risk. Trindle is provided as is, with no warranty of any kind, and you use it entirely at your own risk. It changes how the computer starts, logs in and manages its disks. Back up everything that matters first.
The Trindle Installer's first page, with the mark at the start of a line of eight steps and boxes for language, keyboard and time