···

       
1
       
1
       
 
       
# NixOS {#sec-nixos-state}

     

       
2
       
2
       
 
       


     

       
3
       
3
       
-
       
NixOS itself obviously needs `/nix` to be persistent, so the system environment

     

       
4
       
4
       
-
       
can be linked from the nix store during activation.

     

       
3
       
3
       
+
       
## `/nix` {#sec-state-nix}

     

       
5
       
4
       
 
       


     

       
6
       
6
       
-
       
Moreover, `/boot` should also be persistent, as it contains the kernel, initrd,

     

       
7
       
7
       
-
       
and the command-line determining the system environment's path in the nix store.

     

       
5
       
5
       
+
       
NixOS needs the entirety of `/nix` to be persistent, as it includes:

     

       
6
       
6
       
+
       
- `/nix/store`, which contains all the system's executables, libraries, and supporting data;

     

       
7
       
7
       
+
       
- `/nix/var/nix`, which contains:

     

       
8
       
8
       
+
       
  - the Nix daemon's database;

     

       
9
       
9
       
+
       
  - roots whose transitive closure is preserved when garbage-collecting the Nix store;

     

       
10
       
10
       
+
       
  - system-wide and per-user profiles.

     

       
11
       
11
       
+
       


     

       
12
       
12
       
+
       
## `/boot` {#sec-state-boot}

     

       
13
       
13
       
+
       


     

       
14
       
14
       
+
       
`/boot` should also be persistent, as it contains:

     

       
15
       
15
       
+
       
- the kernel and initrd which the bootloader loads,

     

       
16
       
16
       
+
       
- the bootloader's configuration, including the kernel's command-line which

     

       
17
       
17
       
+
       
  determines the store path to use as system environment.

     

       
8
       
18
       
 
       


     

       
9
       
19
       
 
       


     

       
10
       
20
       
 
       
## Users and groups {#sec-state-users}