chore(immich): add backup and restore procedure

knowledge base/immich.md

@@ -4,6 +4,7 @@ Self-hosted photo and video management solution.
 
 1. [TL;DR](#tldr)
 1. [Further readings](#further-readings)
+   1. [Sources](#sources)
 
 ## TL;DR
 
@@ -23,15 +24,28 @@ The composition uses `.env` for configuration.<br/>
 Refer the [Environment Variables] documentation page for the available environment variables.
 </details>
 
-<!-- Uncomment if used
 <details>
   <summary>Usage</summary>
 
 ```sh
+# Backup the DB.
+docker exec -t 'immich_postgres' pg_dumpall --clean --if-exists --username='postgres' \
+| gzip > '/path/to/backup/dump.sql.gz'
+
+# Restore the DB.
+# The procedure deletes *all* data to start from scratch.
+source '.env' \
+&& docker compose down -v \
+&& rm -rf "$DB_DATA_LOCATION" \
+&& docker compose create \
+&& docker start 'immich_postgres' && sleep 10 \
+&& gunzip < '/path/to/backup/dump.sql.gz' \
+  | sed "s/SELECT pg_catalog.set_config('search_path', '', false);/SELECT pg_catalog.set_config('search_path', 'public, pg_catalog', true);/g" \
+  | docker exec -i 'immich_postgres' psql --username='postgres' \
+&& docker compose up -d
 ```
 
 </details>
--->
 
 <!-- Uncomment if used
 <details>
@@ -49,6 +63,10 @@ Refer the [Environment Variables] documentation page for the available environme
 - [Main repository]
 - [Environment Variables]
 
+### Sources
+
+- [Backup and Restore]
+
 <!--
   Reference
   ═╬═Time══
@@ -58,6 +76,7 @@ Refer the [Environment Variables] documentation page for the available environme
 <!-- Knowledge base -->
 <!-- Files -->
 <!-- Upstream -->
+[backup and restore]: https://immich.app/docs/administration/backup-and-restore
 [environment variables]: https://immich.app/docs/install/environment-variables
 [main repository]: https://github.com/immich-app/immich
 [website]: https://immich.app/

knowledge base/self-hosting.md

@@ -18,11 +18,11 @@ The _art_ of hosting and managing applications on one's own servers instead of c
 | [Gitlab]         | Git server                          | [Gitea], [Gogs]                           |
 | [Gogs]           | Git server                          | [Gitea], [Gitlab]                         |
 | [Home Assistant] | Home automation platform            |                                           |
-| [Immich]         | Photo and video management solution | Google Photo                              |
+| [Immich]         | Photo and video management solution | Google Photo, [PhotoPrism]                |
 | [NextCloud]      | File sharing platform               | [OwnCloud]                                |
 | [OpenMediaVault] | NAS solution                        | [TrueNAS]                                 |
 | [Paperless-ngx]  | Document management system          |                                           |
-| [PhotoPrism]     | Google Photos replacement           |                                           |
+| [PhotoPrism]     | Photo and video management solution | Google Photo, [Immich]                    |
 | [Rundeck]        | Task runner                         | [AWX], [CTFreak], [Semaphore], [Zuul]     |
 | [Semaphore]      | Task runner                         | [AWX], [CTFreak], [Rundeck], [Zuul]       |
 | [Uptime Kuma]    | Status page                         | [Gatus], [Statping-ng], [Vigil]           |