diff --git a/operating-systems/buer.scm b/operating-systems/buer.scm
index b56da36..99d0754 100644
--- a/operating-systems/buer.scm
+++ b/operating-systems/buer.scm
@@ -6,7 +6,6 @@
 
   #|GNU packages|#
   #|A|# #:use-module (gnu packages admin)
-        #:use-module (gnu packages android)
   #|B|# #:use-module (gnu packages base)
   #|C|# #:use-module (gnu packages certs)
         #:use-module (gnu packages compression)
@@ -16,6 +15,8 @@
   #|L|# #:use-module (gnu packages less)
         #:use-module (gnu packages linux)
   #|M|# #:use-module (gnu packages man)
+  #|P|# #:use-module (gnu packages package-management)
+        #:use-module (gnu packages pciutils)
   #|S|# #:use-module (gnu packages shells)
   #|T|# #:use-module (gnu packages texinfo)
   #|V|# #:use-module (gnu packages vpn)
@@ -57,11 +58,12 @@
   #|M|# #:use-module (radix system monitoring)
 
   #|Buer|#
-  #|S|# #:use-module (buer secrets)
+  #|B|# #:use-module ((buer build-machines) #:prefix build-machine:)
+  #|C|# #:use-module ((buer channels) #:prefix channel:)
+  #|U|# #:use-module ((buer users) #:prefix user:)
 
   #|Buer files|#
   #|S|# #:use-module ((buer files substitute-keys) #:prefix substitute-key:)
-        #:use-module ((buer files ssh-keys) #:prefix ssh-key:)
   #|T|# #:use-module ((buer files thinkfan)        #:prefix file:thinkfan-)
 
   #|SRFIs|#
@@ -69,26 +71,6 @@
 
   #:export (operating-system))
 
-(define user:radio
-  (user-account
-   (name "radio")
-   (password %radio-password)
-   (home-directory "/home/radio")
-   (shell (file-append fish "/bin/fish"))
-   (uid 1000)
-   (group "users")
-   (supplementary-groups `("audio" "seat" "video" "wheel"))))
-
-(define user:root
-  (user-account
-   (name "root")
-   (password %root-password)
-   (system? #t)
-   (home-directory "/root")
-   (uid 0)
-   (group "root")
-   (shell (file-append dash-next "/bin/dash"))))
-
 (define operating-system
   (gnu:operating-system
    (host-name "buer")
@@ -154,8 +136,9 @@
           #|guile       |# guile-next guile-colorized guile-readline
           #|less        |# less
           #|linux       |# e2fsprogs iproute kmod linux-libre-documentation
-                           procps psmisc util-linux
+                           procps psmisc usbutils util-linux
           #|man         |# man-db man-pages
+          #|pciutils    |# pciutils
           #|shells      |# dash-next
           #|texinfo     |# info-reader
           #|text-editors|# kakoune
@@ -189,7 +172,7 @@
           (service seatd-service-type)
           (service greetd-service-type
                    (greetd-configuration
-                    (greeter-supplementary-groups '("seat" "video"))
+                    (greeter-supplementary-groups `("seat" "video"))
                     (terminals
                       (map (lambda (x)
                              (greetd-terminal-configuration
@@ -222,21 +205,14 @@
           #|Guix services|#
           (service guix-service-type
                    (guix-configuration
-                    (discover? #t)
                     (build-accounts 16)
-                  #;(build-machines
-                     (list #~(build-machine
-                              (name "yumiko")
-                              (systems (list "x86_64-linux"))
-                              (host-key #$(plain-file-content
-                                            ssh-key:yumiko.pub))
-                              (private-key "/root/.ssh/id_ed25519")
-                              (user "radio")
-                              (port 2222))))
+                    (discover? #t)
+                    (guix (guix-for-channels
+                            (list channel:guix
+                                  channel:radix)))
                     (substitute-urls
-                     (cons* #;"http://substitutes.yumiko:8081"
-                            "https://berlin.guix.gnu.org"
-                            %default-substitute-urls))
+                     (cons "https://berlin.guix.gnu.org"
+                           %default-substitute-urls))
                     (authorized-keys
                      (cons* substitute-key:yuria.pub
                             substitute-key:yumiko.pub
@@ -308,12 +284,11 @@
                    (thinkfan-configuration
                     (thinkfan thinkfan-next)
                     (config-file file:thinkfan-config)))
-          (service thermald-service-type)
 
           #|Memory management services|#
           (service zram-device-service-type
                    (zram-device-configuration
-                    (size (round/ (ram-total) 4))
+                    (size (round/ (ram-total) 2))
                     (compression-algorithm 'lz4)))
 
           #|Doas configuration services|#
@@ -349,11 +324,13 @@
                                                          (list action service)))))
                                     '(networking wpa-supplicant)
                                     '(doc stop start enable status restart disable)))
+
           #|Special file services|#
           (service special-files-service-type
                    `(("/bin/sh"      ,(file-append dash-next "/bin/dash"))
                      ("/usr/bin/env" ,(file-append coreutils "/bin/env"))))
 
+          #|Sysctl services|#
           (simple-service 'extra-sysctl-settings sysctl-service-type
                           `(("vm.swappiness" . "180")
                             ("vm.watermark_boost_factor" . "0")
diff --git a/operating-systems/buer/build-machines.scm b/operating-systems/buer/build-machines.scm
new file mode 100644
index 0000000..50173b7
--- /dev/null
+++ b/operating-systems/buer/build-machines.scm
@@ -0,0 +1,14 @@
+(define-module (buer build-machines)
+  #:use-module ((buer files ssh-keys) #:prefix ssh-key:)
+  #:use-module (guix gexp)
+
+  #:export (yumiko))
+
+(define yumiko
+  #~(build-machine
+      (name "yumiko")
+      (systems (list "x86_64-linux"))
+      (host-key #$(plain-file-content ssh-key:yumiko.pub))
+      (private-key "/root/.ssh/id_ed25519")
+      (user "radio")
+      (port 2222)))
diff --git a/operating-systems/buer/channels.scm b/operating-systems/buer/channels.scm
new file mode 100644
index 0000000..159a843
--- /dev/null
+++ b/operating-systems/buer/channels.scm
@@ -0,0 +1,27 @@
+(define-module (buer channels)
+  #:use-module (guix channels)
+  #:use-module (gnu packages package-management)
+
+  #:export (guix radix))
+
+(define guix
+  (channel
+    (name 'guix)
+    (url "https://git.savannah.gnu.org/git/guix.git")
+    (branch "master")
+    (introduction
+      (make-channel-introduction
+        "9edb3f66fd807b096b48283debdcddccfea34bad"
+        (openpgp-fingerprint
+          "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA")))))
+
+(define radix
+  (channel
+    (name 'radix)
+    (url "https://codeberg.org/anemofilia/radix.git")
+    (branch "main")
+    (introduction
+      (make-channel-introduction
+        "f9130e11e35d2c147c6764ef85542dc58dc09c4f"
+        (openpgp-fingerprint
+          "F164 709E 5FC7 B32B AEC7  9F37 1F2E 76AC E3F5 31C8")))))
diff --git a/operating-systems/buer/users.scm b/operating-systems/buer/users.scm
new file mode 100644
index 0000000..7222657
--- /dev/null
+++ b/operating-systems/buer/users.scm
@@ -0,0 +1,27 @@
+(define-module (buer users)
+  #:use-module (buer secrets)
+  #:use-module (gnu packages shells)
+  #:use-module (radix packages shells)
+  #:use-module (gnu system accounts)
+  #:use-module (guix gexp)
+
+  #:export (radio root))
+
+(define radio
+  (user-account
+   (name "radio")
+   (password %radio-password)
+   (home-directory "/home/radio")
+   (shell (file-append fish "/bin/fish"))
+   (uid 1000)
+   (group "users")
+   (supplementary-groups `("audio" "seat" "video" "wheel"))))
+
+(define root
+  (user-account
+   (name "root")
+   (password %root-password)
+   (home-directory "/root")
+   (uid 0)
+   (group "root")
+   (shell (file-append dash-next "/bin/dash"))))