diff --git a/.config/bash/module/Nix.sh b/.config/bash/module/Nix.sh
index 4381009..b530705 100644
--- a/.config/bash/module/Nix.sh
+++ b/.config/bash/module/Nix.sh
@@ -34,7 +34,19 @@ function nix_channel() {
 	nix-channel --list
 }
 
-# Update system (rebuild).
+# Rebuild system.
+# Optionally force the hostname.
+# Usage: nix_rebuild [HOSTNAME]
+function nix_rebuild() {
+	local target="${1}"
+	[[ "${target}" = "" ]] && target="${HOSTNAME}"
+
+	cd ${HOME}/.config/linux/system
+	nixos-rebuild switch --flake .#${target}
+	cd -
+}
+
+# Update system.
 # Optionally force the hostname.
 # Usage: nix_update [HOSTNAME]
 function nix_update() {
@@ -42,18 +54,8 @@ function nix_update() {
 	[[ "${target}" = "" ]] && target="${HOSTNAME}"
 
 	cd ${HOME}/.config/linux/system
-	nixos-rebuild switch --flake .#${target}
-}
-
-# Upgrade system. Applies after reboot.
-# Optionally force the hostname.
-# Usage: nix_upgrade [HOSTNAME]
-function nix_upgrade() {
-	local target="${1}"
-	[[ "${target}" = "" ]] && target="${HOSTNAME}"
-
-	cd ${HOME}/.config/linux/system
-	nix flake update && nix_update "${target}"
+	nix flake update
+	cd -
 }
 
 # Free up root space.
diff --git a/.config/linux/system/host/home/Configuration.nix b/.config/linux/system/host/home/Configuration.nix
index a605523..cde3718 100644
--- a/.config/linux/system/host/home/Configuration.nix
+++ b/.config/linux/system/host/home/Configuration.nix
@@ -14,7 +14,7 @@
 	networking.extraHosts = ''
 		10.1.0.2 git.voronind.com
 	'';
-	networking.nameservers = [ "1.1.1.1" "8.8.8.8" ];
+	networking.networkmanager.insertNameservers = [ "1.1.1.1" "8.8.8.8" ];
 
 	# Filesystems.
 	fileSystems."/storage/cold_1" = {
diff --git a/.doc/Bash.md b/.doc/Bash.md
index 85e6b97..38eeebe 100644
--- a/.doc/Bash.md
+++ b/.doc/Bash.md
@@ -94,11 +94,10 @@ Command|Description
 
 Command|Description
 ---|---
-`cp <FROM> <TO>`|Replaces default cp with rsync. 
-`cp_merge <FROM> <TO>`|Copy and also merge all changes (delete dst files that do not exist in src). 
+`rcp <FROM> <TO>`|Replaces default cp with rsync. 
+`rcp_merge <FROM> <TO>`|Copy and also merge all changes (delete dst files that do not exist in src). 
 `cp_link <FROM> <TO>`|Copy by creating hardlinks. Works for directories, too. 
-`bcp`|Default cp, a.k.a builtin cp. When you don't need rsync. 
-`cp_test <FROM> <TO>`|Print output of cp_merge without writing anything. 
+`rcp_test <FROM> <TO>`|Print output of cp_merge without writing anything. 
 
 ## Date.
 
@@ -118,8 +117,8 @@ Command|Description
 
 Command|Description
 ---|---
-`df`|Show only physical drives info. 
-`du [DIRS]`|Show combined size in SI. Current dir by default. 
+`pdf`|Show only physical drives info. 
+`tdu [DIRS]`|Show total size in SI. Current dir by default. 
 
 ## Docker.
 
@@ -262,22 +261,15 @@ Command|Description
 `name_replace <OLD> <NEW> [FILES]`|Replace part of the name. All matching files by default. 
 `name_fix_numbering [FILES]`|Fix numbering for numbered files. I.e if there are 10 items and some of them start without zero, then append zero to it. 1..10 -> 01..10. 
 
-## Ncdu.
-
-Command|Description
----|---
-`ncdu [DIRS]`|Search only on current filesystem. Current dir by default. 
-
 ## Nix.
 
 Command|Description
 ---|---
 `nix_find <PACKAGE>`|Find Nix package path. 
 `nix_unstable`|Switch to Unstable branch. 
-`nix_unstable_small`|Switch to Small Unstable branch (for server). 
 `nix_channel`|Display current channel. 
-`nix_update [HOSTNAME]`|Update system (rebuild). Optionally force the hostname. 
-`nix_upgrade [HOSTNAME]`|Upgrade system. Applies after reboot. Optionally force the hostname. 
+`nix_rebuild [HOSTNAME]`|Rebuild system. Optionally force the hostname. 
+`nix_update [HOSTNAME]`|Update system. Optionally force the hostname. 
 `nix_clean`|Free up root space. 
 `nix_shell [NAME]`|Spawn shell with specified nix environment. `Main` is default. 
 `nix_tmpshell <PACKAGES>`|Spawn nix-shell with specified packages. 
@@ -321,11 +313,11 @@ Command|Description
 `parse_startcase <STRING>`|Parse string to start case. 
 `parse_json <STRING>`|Parse string to pretty Json. 
 
-## Permissions.
+## Permission.
 
 Command|Description
 ---|---
-`perm_share`|Recursively change permissions to allow read sharing with group and others.  
+`perm_share`|Recursively change permissions to allow read sharing with group and others. 
 `perm`|Recursively change permissions to restrict access for group and others. 
 
 ## Ps.