chore: improved folder structure

knowledge base/diy nas/v1.md

@@ -4,6 +4,7 @@
 
 1. [Hardware](#hardware)
 1. [Software](#software)
+1. [Folder structure](#folder-structure)
 1. [Further readings](#further-readings)
 1. [Sources](#sources)
 
@@ -28,11 +29,25 @@
 | OS file system   | Default (ext4)   |                                                       |
 | Data file system | ZFS              | See [ZFS on OpenMediaVault](../openmediavault.md#zfs) |
 
-ZFS datasets used as shared folders shall have the following properties:
+The ZFS pool and datasets used as shared folders shall have the following properties:
 - `aclinherit:restricted`;
 - `aclmode:groupmask`;
 - `acltype:posix` + `xattr:sa` until `nfsv4` is supported on Linux.
 
+## Folder structure
+
+```sh
+/tank/            <-- pool
+├── shared/       <-- shared datasets root, 'nobody:users', 'rwsrwsr-x' + 'd:u::rwX,g::rwX,o::rX'
+│   ├── media/
+│   └── oam/
+└── user/         <-- private datasets root, 'user:user', 'rwsr-s---' + 'd:u::rwX,g::rX,o::-'
+    ├── archive/
+    ├── docs/
+    ├── oam/
+    └── work/
+```
+
 ## Further readings
 
 - [OpenMediaVault]