diff --git a/nixos/tests/hibernate.nix b/nixos/tests/hibernate.nix
index cb75322ca5f9..4d0b53e95b32 100644
--- a/nixos/tests/hibernate.nix
+++ b/nixos/tests/hibernate.nix
@@ -63,7 +63,7 @@ in makeTest {
         # Small root disk for installer
         512
       ];
-      virtualisation.bootDevice = "/dev/vdb";
+      virtualisation.rootDevice = "/dev/vdb";
     };
   };
 
diff --git a/nixos/tests/initrd-luks-empty-passphrase.nix b/nixos/tests/initrd-luks-empty-passphrase.nix
index 41765a395ec6..d2805f2f1734 100644
--- a/nixos/tests/initrd-luks-empty-passphrase.nix
+++ b/nixos/tests/initrd-luks-empty-passphrase.nix
@@ -30,26 +30,26 @@ in {
     specialisation.boot-luks-wrong-keyfile.configuration = {
       boot.initrd.luks.devices = lib.mkVMOverride {
         cryptroot = {
-          device = "/dev/vdc";
+          device = "/dev/vdb";
           keyFile = "/etc/cryptroot.key";
           tryEmptyPassphrase = true;
           fallbackToPassword = !systemdStage1;
         };
       };
-      virtualisation.bootDevice = "/dev/mapper/cryptroot";
+      virtualisation.rootDevice = "/dev/mapper/cryptroot";
       boot.initrd.secrets."/etc/cryptroot.key" = keyfile;
     };
 
     specialisation.boot-luks-missing-keyfile.configuration = {
       boot.initrd.luks.devices = lib.mkVMOverride {
         cryptroot = {
-          device = "/dev/vdc";
+          device = "/dev/vdb";
           keyFile = "/etc/cryptroot.key";
           tryEmptyPassphrase = true;
           fallbackToPassword = !systemdStage1;
         };
       };
-      virtualisation.bootDevice = "/dev/mapper/cryptroot";
+      virtualisation.rootDevice = "/dev/mapper/cryptroot";
     };
   };
 
@@ -76,7 +76,7 @@ in {
 
     # Create encrypted volume
     machine.wait_for_unit("multi-user.target")
-    machine.succeed("echo "" | cryptsetup luksFormat /dev/vdc --batch-mode")
+    machine.succeed("echo "" | cryptsetup luksFormat /dev/vdb --batch-mode")
     machine.succeed("bootctl set-default nixos-generation-1-specialisation-boot-luks-wrong-keyfile.conf")
     machine.succeed("sync")
     machine.crash()
diff --git a/nixos/tests/installer.nix b/nixos/tests/installer.nix
index d441765fe194..f385a99ce652 100644
--- a/nixos/tests/installer.nix
+++ b/nixos/tests/installer.nix
@@ -316,8 +316,9 @@ let
           # installer. This ensures the target disk (/dev/vda) is
           # the same during and after installation.
           virtualisation.emptyDiskImages = [ 512 ];
-          virtualisation.bootDevice =
+          virtualisation.rootDevice =
             if grubVersion == 1 then "/dev/disk/by-id/scsi-0QEMU_QEMU_HARDDISK_drive2" else "/dev/vdb";
+          virtualisation.bootLoaderDevice = "/dev/vda";
           virtualisation.qemu.diskInterface =
             if grubVersion == 1 then "scsi" else "virtio";
 
diff --git a/nixos/tests/luks.nix b/nixos/tests/luks.nix
index 82f5095cb260..c2b95c6a95fb 100644
--- a/nixos/tests/luks.nix
+++ b/nixos/tests/luks.nix
@@ -18,10 +18,10 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
       boot-luks.configuration = {
         boot.initrd.luks.devices = lib.mkVMOverride {
           # We have two disks and only type one password - key reuse is in place
-          cryptroot.device = "/dev/vdc";
-          cryptroot2.device = "/dev/vdd";
+          cryptroot.device = "/dev/vdb";
+          cryptroot2.device = "/dev/vdc";
         };
-        virtualisation.bootDevice = "/dev/mapper/cryptroot";
+        virtualisation.rootDevice = "/dev/mapper/cryptroot";
       };
       boot-luks-custom-keymap.configuration = lib.mkMerge [
         boot-luks.configuration
@@ -37,8 +37,8 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
   testScript = ''
     # Create encrypted volume
     machine.wait_for_unit("multi-user.target")
+    machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdb -")
     machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdc -")
-    machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdd -")
 
     # Boot from the encrypted disk
     machine.succeed("bootctl set-default nixos-generation-1-specialisation-boot-luks.conf")
diff --git a/nixos/tests/lvm2/systemd-stage-1.nix b/nixos/tests/lvm2/systemd-stage-1.nix
index 617ba77b1796..b711cd22d7f4 100644
--- a/nixos/tests/lvm2/systemd-stage-1.nix
+++ b/nixos/tests/lvm2/systemd-stage-1.nix
@@ -1,18 +1,18 @@
 { kernelPackages ? null, flavour }: let
   preparationCode = {
     raid = ''
-      machine.succeed("vgcreate test_vg /dev/vdc /dev/vdd")
+      machine.succeed("vgcreate test_vg /dev/vdb /dev/vdc")
       machine.succeed("lvcreate -L 512M --type raid0 test_vg -n test_lv")
     '';
 
     thinpool = ''
-      machine.succeed("vgcreate test_vg /dev/vdc")
+      machine.succeed("vgcreate test_vg /dev/vdb")
       machine.succeed("lvcreate -L 512M -T test_vg/test_thin_pool")
       machine.succeed("lvcreate -n test_lv -V 16G --thinpool test_thin_pool test_vg")
     '';
 
     vdo = ''
-      machine.succeed("vgcreate test_vg /dev/vdc")
+      machine.succeed("vgcreate test_vg /dev/vdb")
       machine.succeed("lvcreate --type vdo -n test_lv -L 6G -V 12G test_vg/vdo_pool_lv")
     '';
   }.${flavour};
@@ -79,7 +79,7 @@ in import ../make-test-python.nix ({ pkgs, ... }: {
       kernelPackages = lib.mkIf (kernelPackages != null) kernelPackages;
     };
 
-    specialisation.boot-lvm.configuration.virtualisation.bootDevice = "/dev/test_vg/test_lv";
+    specialisation.boot-lvm.configuration.virtualisation.rootDevice = "/dev/test_vg/test_lv";
   };
 
   testScript = ''
diff --git a/nixos/tests/non-default-filesystems.nix b/nixos/tests/non-default-filesystems.nix
index 7fa75aaad724..d4e8bfbc65e9 100644
--- a/nixos/tests/non-default-filesystems.nix
+++ b/nixos/tests/non-default-filesystems.nix
@@ -5,9 +5,10 @@ import ./make-test-python.nix ({ lib, pkgs, ... }:
   nodes.machine =
     { config, pkgs, lib, ... }:
     let
-      disk = config.virtualisation.bootDevice;
+      disk = config.virtualisation.rootDevice;
     in
     {
+      virtualisation.rootDevice = "/dev/vda";
       virtualisation.useDefaultFilesystems = false;
 
       boot.initrd.availableKernelModules = [ "btrfs" ];
diff --git a/nixos/tests/swap-file-btrfs.nix b/nixos/tests/swap-file-btrfs.nix
index 4f73942b5f32..d9fcd2be1160 100644
--- a/nixos/tests/swap-file-btrfs.nix
+++ b/nixos/tests/swap-file-btrfs.nix
@@ -9,7 +9,7 @@ import ./make-test-python.nix ({ lib, ... }:
     {
       virtualisation.useDefaultFilesystems = false;
 
-      virtualisation.bootDevice = "/dev/vda";
+      virtualisation.rootDevice = "/dev/vda";
 
       boot.initrd.postDeviceCommands = ''
         ${pkgs.btrfs-progs}/bin/mkfs.btrfs --label root /dev/vda
diff --git a/nixos/tests/swap-partition.nix b/nixos/tests/swap-partition.nix
index 2279630b57b8..ddcaeb95453e 100644
--- a/nixos/tests/swap-partition.nix
+++ b/nixos/tests/swap-partition.nix
@@ -7,7 +7,7 @@ import ./make-test-python.nix ({ lib, pkgs, ... }:
     {
       virtualisation.useDefaultFilesystems = false;
 
-      virtualisation.bootDevice = "/dev/vda1";
+      virtualisation.rootDevice = "/dev/vda1";
 
       boot.initrd.postDeviceCommands = ''
         if ! test -b /dev/vda1; then
diff --git a/nixos/tests/systemd-initrd-btrfs-raid.nix b/nixos/tests/systemd-initrd-btrfs-raid.nix
index 40fd2d4dc611..c9cdf0060b1b 100644
--- a/nixos/tests/systemd-initrd-btrfs-raid.nix
+++ b/nixos/tests/systemd-initrd-btrfs-raid.nix
@@ -21,14 +21,14 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
       fileSystems = lib.mkVMOverride {
         "/".fsType = lib.mkForce "btrfs";
       };
-      virtualisation.bootDevice = "/dev/vdc";
+      virtualisation.rootDevice = "/dev/vdb";
     };
   };
 
   testScript = ''
     # Create RAID
-    machine.succeed("mkfs.btrfs -d raid0 /dev/vdc /dev/vdd")
-    machine.succeed("mkdir -p /mnt && mount /dev/vdc /mnt && echo hello > /mnt/test && umount /mnt")
+    machine.succeed("mkfs.btrfs -d raid0 /dev/vdb /dev/vdc")
+    machine.succeed("mkdir -p /mnt && mount /dev/vdb /mnt && echo hello > /mnt/test && umount /mnt")
 
     # Boot from the RAID
     machine.succeed("bootctl set-default nixos-generation-1-specialisation-boot-btrfs-raid.conf")
@@ -38,7 +38,7 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
 
     # Ensure we have successfully booted from the RAID
     assert "(initrd)" in machine.succeed("systemd-analyze")  # booted with systemd in stage 1
-    assert "/dev/vdc on / type btrfs" in machine.succeed("mount")
+    assert "/dev/vdb on / type btrfs" in machine.succeed("mount")
     assert "hello" in machine.succeed("cat /test")
     assert "Total devices 2" in machine.succeed("btrfs filesystem show")
   '';
diff --git a/nixos/tests/systemd-initrd-luks-fido2.nix b/nixos/tests/systemd-initrd-luks-fido2.nix
index 133e552a3dc9..e80d95f79c7e 100644
--- a/nixos/tests/systemd-initrd-luks-fido2.nix
+++ b/nixos/tests/systemd-initrd-luks-fido2.nix
@@ -19,19 +19,19 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
     specialisation.boot-luks.configuration = {
       boot.initrd.luks.devices = lib.mkVMOverride {
         cryptroot = {
-          device = "/dev/vdc";
+          device = "/dev/vdb";
           crypttabExtraOpts = [ "fido2-device=auto" ];
         };
       };
-      virtualisation.bootDevice = "/dev/mapper/cryptroot";
+      virtualisation.rootDevice = "/dev/mapper/cryptroot";
     };
   };
 
   testScript = ''
     # Create encrypted volume
     machine.wait_for_unit("multi-user.target")
-    machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdc -")
-    machine.succeed("PASSWORD=supersecret SYSTEMD_LOG_LEVEL=debug systemd-cryptenroll --fido2-device=auto /dev/vdc |& systemd-cat")
+    machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdb -")
+    machine.succeed("PASSWORD=supersecret SYSTEMD_LOG_LEVEL=debug systemd-cryptenroll --fido2-device=auto /dev/vdb |& systemd-cat")
 
     # Boot from the encrypted disk
     machine.succeed("bootctl set-default nixos-generation-1-specialisation-boot-luks.conf")
diff --git a/nixos/tests/systemd-initrd-luks-keyfile.nix b/nixos/tests/systemd-initrd-luks-keyfile.nix
index 25c0c5bd866d..257243d92a1d 100644
--- a/nixos/tests/systemd-initrd-luks-keyfile.nix
+++ b/nixos/tests/systemd-initrd-luks-keyfile.nix
@@ -27,11 +27,11 @@ in {
     specialisation.boot-luks.configuration = {
       boot.initrd.luks.devices = lib.mkVMOverride {
         cryptroot = {
-          device = "/dev/vdc";
+          device = "/dev/vdb";
           keyFile = "/etc/cryptroot.key";
         };
       };
-      virtualisation.bootDevice = "/dev/mapper/cryptroot";
+      virtualisation.rootDevice = "/dev/mapper/cryptroot";
       boot.initrd.secrets."/etc/cryptroot.key" = keyfile;
     };
   };
@@ -39,7 +39,7 @@ in {
   testScript = ''
     # Create encrypted volume
     machine.wait_for_unit("multi-user.target")
-    machine.succeed("cryptsetup luksFormat -q --iter-time=1 -d ${keyfile} /dev/vdc")
+    machine.succeed("cryptsetup luksFormat -q --iter-time=1 -d ${keyfile} /dev/vdb")
 
     # Boot from the encrypted disk
     machine.succeed("bootctl set-default nixos-generation-1-specialisation-boot-luks.conf")
diff --git a/nixos/tests/systemd-initrd-luks-password.nix b/nixos/tests/systemd-initrd-luks-password.nix
index 55d0b4324b40..2dd3f304e82a 100644
--- a/nixos/tests/systemd-initrd-luks-password.nix
+++ b/nixos/tests/systemd-initrd-luks-password.nix
@@ -19,10 +19,10 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
     specialisation.boot-luks.configuration = {
       boot.initrd.luks.devices = lib.mkVMOverride {
         # We have two disks and only type one password - key reuse is in place
-        cryptroot.device = "/dev/vdc";
-        cryptroot2.device = "/dev/vdd";
+        cryptroot.device = "/dev/vdb";
+        cryptroot2.device = "/dev/vdc";
       };
-      virtualisation.bootDevice = "/dev/mapper/cryptroot";
+      virtualisation.rootDevice = "/dev/mapper/cryptroot";
       # test mounting device unlocked in initrd after switching root
       virtualisation.fileSystems."/cryptroot2".device = "/dev/mapper/cryptroot2";
     };
@@ -31,9 +31,9 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
   testScript = ''
     # Create encrypted volume
     machine.wait_for_unit("multi-user.target")
+    machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdb -")
     machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdc -")
-    machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdd -")
-    machine.succeed("echo -n supersecret | cryptsetup luksOpen   -q               /dev/vdd cryptroot2")
+    machine.succeed("echo -n supersecret | cryptsetup luksOpen   -q               /dev/vdc cryptroot2")
     machine.succeed("mkfs.ext4 /dev/mapper/cryptroot2")
 
     # Boot from the encrypted disk
@@ -47,7 +47,7 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
     machine.send_console("supersecret\n")
     machine.wait_for_unit("multi-user.target")
 
-    assert "/dev/mapper/cryptroot on / type ext4" in machine.succeed("mount")
+    assert "/dev/mapper/cryptroot on / type ext4" in machine.succeed("mount"), "/dev/mapper/cryptroot do not appear in mountpoints list"
     assert "/dev/mapper/cryptroot2 on /cryptroot2 type ext4" in machine.succeed("mount")
   '';
 })
diff --git a/nixos/tests/systemd-initrd-luks-tpm2.nix b/nixos/tests/systemd-initrd-luks-tpm2.nix
index 085088d2ee25..734ef38579f0 100644
--- a/nixos/tests/systemd-initrd-luks-tpm2.nix
+++ b/nixos/tests/systemd-initrd-luks-tpm2.nix
@@ -21,11 +21,11 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
     specialisation.boot-luks.configuration = {
       boot.initrd.luks.devices = lib.mkVMOverride {
         cryptroot = {
-          device = "/dev/vdc";
+          device = "/dev/vdb";
           crypttabExtraOpts = [ "tpm2-device=auto" ];
         };
       };
-      virtualisation.bootDevice = "/dev/mapper/cryptroot";
+      virtualisation.rootDevice = "/dev/mapper/cryptroot";
     };
   };
 
@@ -55,8 +55,8 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
 
     # Create encrypted volume
     machine.wait_for_unit("multi-user.target")
-    machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdc -")
-    machine.succeed("PASSWORD=supersecret SYSTEMD_LOG_LEVEL=debug systemd-cryptenroll --tpm2-pcrs= --tpm2-device=auto /dev/vdc |& systemd-cat")
+    machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdb -")
+    machine.succeed("PASSWORD=supersecret SYSTEMD_LOG_LEVEL=debug systemd-cryptenroll --tpm2-pcrs= --tpm2-device=auto /dev/vdb |& systemd-cat")
 
     # Boot from the encrypted disk
     machine.succeed("bootctl set-default nixos-generation-1-specialisation-boot-luks.conf")
diff --git a/nixos/tests/systemd-initrd-swraid.nix b/nixos/tests/systemd-initrd-swraid.nix
index 28a0fb3192ae..d201ba99a204 100644
--- a/nixos/tests/systemd-initrd-swraid.nix
+++ b/nixos/tests/systemd-initrd-swraid.nix
@@ -20,18 +20,18 @@ import ./make-test-python.nix ({ lib, pkgs, ... }: {
       services.swraid = {
         enable = true;
         mdadmConf = ''
-          ARRAY /dev/md0 devices=/dev/vdc,/dev/vdd
+          ARRAY /dev/md0 devices=/dev/vdb,/dev/vdc
         '';
       };
       kernelModules = [ "raid0" ];
     };
 
-    specialisation.boot-swraid.configuration.virtualisation.bootDevice = "/dev/disk/by-label/testraid";
+    specialisation.boot-swraid.configuration.virtualisation.rootDevice = "/dev/disk/by-label/testraid";
   };
 
   testScript = ''
     # Create RAID
-    machine.succeed("mdadm --create --force /dev/md0 -n 2 --level=raid0 /dev/vdc /dev/vdd")
+    machine.succeed("mdadm --create --force /dev/md0 -n 2 --level=raid0 /dev/vdb /dev/vdc")
     machine.succeed("mkfs.ext4 -L testraid /dev/md0")
     machine.succeed("mkdir -p /mnt && mount /dev/md0 /mnt && echo hello > /mnt/test && umount /mnt")
 
diff --git a/nixos/tests/zfs.nix b/nixos/tests/zfs.nix
index bcb9d9bcfd60..e86c53befd28 100644
--- a/nixos/tests/zfs.nix
+++ b/nixos/tests/zfs.nix
@@ -98,15 +98,15 @@ let
         machine.wait_for_unit("multi-user.target")
         machine.succeed(
             "zpool status",
+            "parted --script /dev/vdb mklabel msdos",
+            "parted --script /dev/vdb -- mkpart primary 1024M -1s",
             "parted --script /dev/vdc mklabel msdos",
             "parted --script /dev/vdc -- mkpart primary 1024M -1s",
-            "parted --script /dev/vdd mklabel msdos",
-            "parted --script /dev/vdd -- mkpart primary 1024M -1s",
         )
 
         with subtest("sharesmb works"):
             machine.succeed(
-                "zpool create rpool /dev/vdc1",
+                "zpool create rpool /dev/vdb1",
                 "zfs create -o mountpoint=legacy rpool/root",
                 # shared datasets cannot have legacy mountpoint
                 "zfs create rpool/shared_smb",
@@ -126,8 +126,8 @@ let
         with subtest("encryption works"):
             machine.succeed(
                 'echo password | zpool create -O mountpoint=legacy '
-                + "-O encryption=aes-256-gcm -O keyformat=passphrase automatic /dev/vdc1",
-                "zpool create -O mountpoint=legacy manual /dev/vdd1",
+                + "-O encryption=aes-256-gcm -O keyformat=passphrase automatic /dev/vdb1",
+                "zpool create -O mountpoint=legacy manual /dev/vdc1",
                 "echo otherpass | zfs create "
                 + "-o encryption=aes-256-gcm -o keyformat=passphrase manual/encrypted",
                 "bootctl set-default nixos-generation-1-specialisation-encryption.conf",
@@ -153,7 +153,7 @@ let
             machine.succeed(
                 "rm /etc/hostid",
                 "zgenhostid deadcafe",
-                "zpool create forcepool /dev/vdc1 -O mountpoint=legacy",
+                "zpool create forcepool /dev/vdb1 -O mountpoint=legacy",
                 "bootctl set-default nixos-generation-1-specialisation-forcepool.conf",
                 "rm /etc/hostid",
                 "sync",