add desktop

content/utilities.md

@@ -161,9 +161,46 @@ sections:
     kicker: "Backups"
     headline: "How the backups work."
     body: |
+      Once a day, shortly after midnight, restic backs up your home folder to `.backup-{machine name}` in your Nextcloud files. If the computer was off or you weren't logged in, it runs at your next login instead, once Nextcloud can be reached. It runs at the lowest priority, so it stays out of the way of whatever you're doing, and it only uploads what changed since the last backup.
+
       restic reaches Nextcloud directly through rclone, with its own Nextcloud app password, so the backup doesn't depend on the `/mnt` mount. The Nextcloud app passwords configure creates can be revoked in Nextcloud under **Settings › Security**.
 
-      To leave out more, list paths in `~/.config/coredesktop/backup-exclude`, one per line.
+      If a backup fails, a notification tells you. If only a few files couldn't be read, the rest are still backed up, and the log names the ones it skipped.
+
+      ### How many backups are kept
+
+      restic calls each backup a snapshot. After each backup, it removes older snapshots and keeps:
+
+      - the latest from each of the last **7 days**
+      - the latest from each of the last **4 weeks**
+      - the latest from each of the last **6 months**
+
+      One snapshot can count for more than one of these, so there are usually about 15 snapshots, going back about six months. Days, weeks and months with no backup, such as when the computer was off, don't count, so the oldest snapshot can be older than that. A file that's in several snapshots is stored only once, so keeping them all takes little more space than one full copy plus what's changed.
+
+      ### What's left out
+
+      The backup is for what you can't get back any other way. It leaves out things that can be downloaded, reinstalled or rebuilt, which keeps it smaller and quicker and saves space in your Nextcloud:
+
+      - **Caches and the trash.** `~/.cache`, `~/.local/share/Trash`, the cache for the `/mnt` mount, Flatpak apps' caches, the caches Electron and Chromium apps (Element, browsers, editors) keep in `~/.config`, and any folder marked as a cache with a `CACHEDIR.TAG` file.
+      - **Apps and tools that can be installed again.** Flatpak apps, Podman containers and images, CoreDesktop's own files and sibling projects, package caches (npm, bun, Cargo, Go), and what mise, uv, pipx, Claude Code and Neovim's plugins install.
+      - **The AI agents' programs and downloads.** Their settings, memories and sessions are backed up.
+      - **LM Studio's models and engines.** They're large and can be downloaded again.
+      - **Element's search index** for encrypted messages, which Element rebuilds.
+      - **WinBoat's Windows VM** (`~/winboat`). Its disk is large and changes whenever Windows runs, so most of it would be uploaded every day.
+      - **Other drives and btrfs subvolumes** mounted inside your home folder.
+
+      To leave out more, list paths or patterns in `~/.config/coredesktop/backup-exclude`, one per line, e.g. `$HOME/Videos` or `*.iso`.
+
+      ### Turning backups off
+
+      Run `configure backup` and choose **Turn backups off**. This stops the daily backup, and any backup that's running.
+
+      The backups made so far stay in your Nextcloud files, and configure asks whether to delete them:
+
+      - **Keep them** (the default). You can still restore from them as shown below, as your passphrase and app password stay in your keyring. To turn backups back on, run `configure backup`; they carry on in the same folder.
+      - **Delete them.** Type the folder name to confirm. configure deletes the folder, revokes the backup's Nextcloud app password, and removes the passphrase and app password from your keyring. Nextcloud keeps the folder in its trash bin, where it still uses your storage, until you empty it. After that, the backups are gone for good.
+
+      ### Checking on it
 
       ```
       systemctl --user list-timers coredesktop-backup.timer