diff --git a/lib/test-driver/test-driver.pl b/lib/test-driver/test-driver.pl
index 0fdcf97af67..43f74cf404b 100644
--- a/lib/test-driver/test-driver.pl
+++ b/lib/test-driver/test-driver.pl
@@ -68,6 +68,14 @@ sub startAll {
 }
 
 
+# Wait until all VMs have terminated.
+sub joinAll {
+    $log->nest("waiting for all VMs to finish", sub {
+        $_->waitForShutdown foreach values %vms;
+    });
+}
+
+
 # In interactive tests, this allows the non-interactive test script to
 # be executed conveniently.
 sub testScript {
diff --git a/lib/testing.nix b/lib/testing.nix
index 704ee4025a5..6a39df8c865 100644
--- a/lib/testing.nix
+++ b/lib/testing.nix
@@ -157,7 +157,7 @@ rec {
         ln -s ${testDriver}/bin/nixos-test-driver $out/bin/nixos-run-vms
         wrapProgram $out/bin/nixos-run-vms \
           --add-flags "$vms" \
-          --set tests '"startAll; sleep 1e9;"' \
+          --set tests '"startAll; joinAll;"' \
           --set VLANS '"${toString vlans}"'
       ''; # "
 
diff --git a/modules/installer/cd-dvd/installation-cd-base.nix b/modules/installer/cd-dvd/installation-cd-base.nix
index ae227dbcb80..375941d2447 100644
--- a/modules/installer/cd-dvd/installation-cd-base.nix
+++ b/modules/installer/cd-dvd/installation-cd-base.nix
@@ -66,5 +66,5 @@ in
 
   # To speed up installation a little bit, include the complete stdenv
   # in the Nix store on the CD.
-  isoImage.storeContents = [ pkgs.stdenv pkgs.klibc pkgs.klibcShrunk ];
+  isoImage.storeContents = [ pkgs.stdenv pkgs.busybox ];
 }
diff --git a/modules/installer/cd-dvd/iso-image.nix b/modules/installer/cd-dvd/iso-image.nix
index cf76151c2ae..7b050f8dd6a 100644
--- a/modules/installer/cd-dvd/iso-image.nix
+++ b/modules/installer/cd-dvd/iso-image.nix
@@ -205,9 +205,7 @@ in
     else
       [ config.boot.kernelPackages.aufs ];
 
-  boot.initrd.availableKernelModules = [ "aufs" "squashfs" "iso9660" ];
-
-  boot.initrd.kernelModules = [ "loop" ];
+  boot.initrd.kernelModules = [ "aufs" "squashfs" "iso9660" "loop" ];
 
   boot.kernelModules = pkgs.stdenv.lib.optional config.isoImage.makeEfiBootable "efivars";
 
diff --git a/modules/installer/cd-dvd/system-tarball-pc.nix b/modules/installer/cd-dvd/system-tarball-pc.nix
index 035b6dd6c0a..ddad520c446 100644
--- a/modules/installer/cd-dvd/system-tarball-pc.nix
+++ b/modules/installer/cd-dvd/system-tarball-pc.nix
@@ -123,7 +123,7 @@ in
 
   # To speed up further installation of packages, include the complete stdenv
   # in the Nix store of the tarball.
-  tarball.storeContents = pkgs2storeContents [ pkgs.stdenv pkgs.klibc pkgs.klibcShrunk ];
+  tarball.storeContents = pkgs2storeContents [ pkgs.stdenv ];
 
   tarball.contents =
     [ { source = config.boot.kernelPackages.kernel + "/" + config.system.boot.loader.kernelFile;
diff --git a/modules/system/boot/stage-1-init.sh b/modules/system/boot/stage-1-init.sh
index b71de50ad39..4e07714eabc 100644
--- a/modules/system/boot/stage-1-init.sh
+++ b/modules/system/boot/stage-1-init.sh
@@ -325,8 +325,7 @@ echo /sbin/modprobe > /proc/sys/kernel/modprobe
 
 
 # Start stage 2.  `switch_root' deletes all files in the ramfs on the
-# current root.  It also moves the /proc, /sys and /dev mounts over to
-# the new root.  Note that $stage2Init might be an absolute symlink,
+# current root.  Note that $stage2Init might be an absolute symlink,
 # in which case "-e" won't work because we're not in the chroot yet.
 if ! test -e "$targetRoot/$stage2Init" -o -L "$targetRoot/$stage2Init"; then
     echo "stage 2 init script ($targetRoot/$stage2Init) not found"
@@ -335,7 +334,9 @@ fi
 
 mkdir -m 0755 -p $targetRoot/proc $targetRoot/sys $targetRoot/dev $targetRoot/run
 
-# `switch_root' doesn't move /run yet, so we have to do it ourselves.
+mount --bind /proc $targetRoot/proc
+mount --bind /sys $targetRoot/sys
+mount --bind /dev $targetRoot/dev
 mount --bind /run $targetRoot/run
 
 exec switch_root "$targetRoot" "$stage2Init"
diff --git a/modules/testing/test-instrumentation.nix b/modules/testing/test-instrumentation.nix
index 468a3030ca6..ce9c1cea743 100644
--- a/modules/testing/test-instrumentation.nix
+++ b/modules/testing/test-instrumentation.nix
@@ -5,20 +5,6 @@
 
 with pkgs.lib;
 
-let
-
-  # Urgh, `socat' sets the SIGCHLD to ignore.  This wreaks havoc with
-  # some programs.
-  rootShell = pkgs.writeScript "shell.pl"
-    ''
-      #! ${pkgs.perl}/bin/perl
-      $SIG{CHLD} = 'DEFAULT';
-      print "\n";
-      exec "/bin/sh";
-    '';
-
-in
-
 {
 
   config = {
@@ -38,7 +24,8 @@ in
             exec < /dev/hvc0 > /dev/hvc0 2> /dev/ttyS0
             echo "connecting to host..." >&2
             stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion
-            ${pkgs.socat}/bin/socat stdio exec:${rootShell}
+            echo
+            PS1= /bin/sh
           '';
       };