diff --git a/nixos/modules/installer/sd-card/sd-image.nix b/nixos/modules/installer/sd-card/sd-image.nix
index d96216c4ae17..0fb725a035e3 100644
--- a/nixos/modules/installer/sd-card/sd-image.nix
+++ b/nixos/modules/installer/sd-card/sd-image.nix
@@ -185,7 +185,7 @@ in
   config = {
     hardware.enableAllHardware = true;
 
-    fileSystems = {
+    fileSystems = lib.mkImageMediaOverride {
       "/boot/firmware" = {
         device = "/dev/disk/by-label/${config.sdImage.firmwarePartitionName}";
         fsType = "vfat";
diff --git a/nixos/modules/virtualisation/azure-image.nix b/nixos/modules/virtualisation/azure-image.nix
index 252381d0f198..fe28efe624c5 100644
--- a/nixos/modules/virtualisation/azure-image.nix
+++ b/nixos/modules/virtualisation/azure-image.nix
@@ -113,7 +113,7 @@ in
       '';
     };
 
-    fileSystems = {
+    fileSystems = lib.mkImageMediaOverride {
       "/" = {
         device = "/dev/disk/by-label/${cfg.label}";
         inherit (cfg) label;
diff --git a/nixos/modules/virtualisation/digital-ocean-config.nix b/nixos/modules/virtualisation/digital-ocean-config.nix
index a38d2d15ab84..14d9b3feb1e4 100644
--- a/nixos/modules/virtualisation/digital-ocean-config.nix
+++ b/nixos/modules/virtualisation/digital-ocean-config.nix
@@ -39,7 +39,7 @@ with lib;
     in
     mkMerge [
       {
-        fileSystems."/" = lib.mkDefault {
+        fileSystems."/" = lib.mkImageMediaOverride {
           device = "/dev/disk/by-label/nixos";
           autoResize = true;
           fsType = "ext4";
diff --git a/nixos/modules/virtualisation/disk-image.nix b/nixos/modules/virtualisation/disk-image.nix
index c524b6627113..ef73e6d4f74a 100644
--- a/nixos/modules/virtualisation/disk-image.nix
+++ b/nixos/modules/virtualisation/disk-image.nix
@@ -37,7 +37,7 @@ in
     boot.loader.systemd-boot.enable = lib.mkDefault cfg.efiSupport;
     boot.growPartition = lib.mkDefault true;
 
-    fileSystems = {
+    fileSystems = lib.mkImageMediaOverride {
       "/" = {
         device = "/dev/disk/by-label/nixos";
         autoResize = true;
diff --git a/nixos/modules/virtualisation/google-compute-config.nix b/nixos/modules/virtualisation/google-compute-config.nix
index 8f9e2b4f4075..c112d4132920 100644
--- a/nixos/modules/virtualisation/google-compute-config.nix
+++ b/nixos/modules/virtualisation/google-compute-config.nix
@@ -21,7 +21,7 @@ in
     ../profiles/qemu-guest.nix
   ];
 
-  fileSystems."/" = {
+  fileSystems."/" = lib.mkImageMediaOverride {
     fsType = "ext4";
     device = "/dev/disk/by-label/nixos";
     autoResize = true;
diff --git a/nixos/modules/virtualisation/hyperv-image.nix b/nixos/modules/virtualisation/hyperv-image.nix
index 8f77d384a9ba..f292a60d71cd 100644
--- a/nixos/modules/virtualisation/hyperv-image.nix
+++ b/nixos/modules/virtualisation/hyperv-image.nix
@@ -73,15 +73,17 @@ in
       inherit config lib pkgs;
     };
 
-    fileSystems."/" = {
-      device = "/dev/disk/by-label/nixos";
-      autoResize = true;
-      fsType = "ext4";
-    };
+    fileSystems = lib.mkImageMediaOverride {
+      "/" = {
+        device = "/dev/disk/by-label/nixos";
+        autoResize = true;
+        fsType = "ext4";
+      };
 
-    fileSystems."/boot" = {
-      device = "/dev/disk/by-label/ESP";
-      fsType = "vfat";
+      "/boot" = {
+        device = "/dev/disk/by-label/ESP";
+        fsType = "vfat";
+      };
     };
 
     boot.growPartition = true;
diff --git a/nixos/modules/virtualisation/kubevirt.nix b/nixos/modules/virtualisation/kubevirt.nix
index 5e855d3af06e..6e91a8b67c6f 100644
--- a/nixos/modules/virtualisation/kubevirt.nix
+++ b/nixos/modules/virtualisation/kubevirt.nix
@@ -12,7 +12,7 @@
   ];
 
   config = {
-    fileSystems."/" = {
+    fileSystems."/" = lib.mkImageMediaOverride {
       device = "/dev/disk/by-label/nixos";
       fsType = "ext4";
       autoResize = true;
diff --git a/nixos/modules/virtualisation/linode-config.nix b/nixos/modules/virtualisation/linode-config.nix
index a6dbe4cbb8f0..721a6f8bdc69 100644
--- a/nixos/modules/virtualisation/linode-config.nix
+++ b/nixos/modules/virtualisation/linode-config.nix
@@ -1,10 +1,8 @@
 {
-  config,
   lib,
   pkgs,
   ...
 }:
-with lib;
 {
   imports = [ ../profiles/qemu-guest.nix ];
 
@@ -12,7 +10,7 @@ with lib;
     enable = true;
 
     settings.PermitRootLogin = "prohibit-password";
-    settings.PasswordAuthentication = mkDefault false;
+    settings.PasswordAuthentication = lib.mkDefault false;
   };
 
   networking = {
@@ -34,13 +32,13 @@ with lib;
     sysstat
   ];
 
-  fileSystems."/" = {
+  fileSystems."/" = lib.mkImageMediaOverride {
     fsType = "ext4";
     device = "/dev/sda";
     autoResize = true;
   };
 
-  swapDevices = mkDefault [ { device = "/dev/sdb"; } ];
+  swapDevices = lib.mkDefault [ { device = "/dev/sdb"; } ];
 
   # Enable LISH and Linode Booting w/ GRUB
   boot = {
diff --git a/nixos/modules/virtualisation/oci-common.nix b/nixos/modules/virtualisation/oci-common.nix
index d92cda7de437..73b68c57f3e2 100644
--- a/nixos/modules/virtualisation/oci-common.nix
+++ b/nixos/modules/virtualisation/oci-common.nix
@@ -30,15 +30,17 @@ in
 
   boot.growPartition = true;
 
-  fileSystems."/" = {
-    device = "/dev/disk/by-label/nixos";
-    fsType = "ext4";
-    autoResize = true;
-  };
+  fileSystems = lib.mkImageMediaOverride {
+    "/" = {
+      device = "/dev/disk/by-label/nixos";
+      fsType = "ext4";
+      autoResize = true;
+    };
 
-  fileSystems."/boot" = lib.mkIf cfg.efi {
-    device = "/dev/disk/by-label/ESP";
-    fsType = "vfat";
+    "/boot" = lib.mkIf cfg.efi {
+      device = "/dev/disk/by-label/ESP";
+      fsType = "vfat";
+    };
   };
 
   boot.loader.efi.canTouchEfiVariables = false;
diff --git a/nixos/modules/virtualisation/openstack-config.nix b/nixos/modules/virtualisation/openstack-config.nix
index caa3cbba6a6b..34031c303039 100644
--- a/nixos/modules/virtualisation/openstack-config.nix
+++ b/nixos/modules/virtualisation/openstack-config.nix
@@ -33,18 +33,22 @@ in
   ];
 
   config = {
-    fileSystems."/" = mkIf (!cfg.zfs.enable) {
-      device = "/dev/disk/by-label/nixos";
-      fsType = "ext4";
-      autoResize = true;
-    };
+    fileSystems."/" = mkIf (!cfg.zfs.enable) (
+      lib.mkImageMediaOverride {
+        device = "/dev/disk/by-label/nixos";
+        fsType = "ext4";
+        autoResize = true;
+      }
+    );
 
-    fileSystems."/boot" = mkIf (cfg.efi || cfg.zfs.enable) {
-      # The ZFS image uses a partition labeled ESP whether or not we're
-      # booting with EFI.
-      device = "/dev/disk/by-label/ESP";
-      fsType = "vfat";
-    };
+    fileSystems."/boot" = mkIf (cfg.efi || cfg.zfs.enable) (
+      lib.mkImageMediaOverride {
+        # The ZFS image uses a partition labeled ESP whether or not we're
+        # booting with EFI.
+        device = "/dev/disk/by-label/ESP";
+        fsType = "vfat";
+      }
+    );
 
     boot.growPartition = true;
     boot.kernelParams = [ "console=tty1" ];
diff --git a/nixos/modules/virtualisation/openstack-options.nix b/nixos/modules/virtualisation/openstack-options.nix
index 9d1b1efd676d..751e1612e833 100644
--- a/nixos/modules/virtualisation/openstack-options.nix
+++ b/nixos/modules/virtualisation/openstack-options.nix
@@ -70,12 +70,14 @@ in
           _: value: ((value.mount or null) != null)
         ) config.openstack.zfs.datasets;
       in
-      lib.mapAttrs' (
-        dataset: opts:
-        lib.nameValuePair opts.mount {
-          device = dataset;
-          fsType = "zfs";
-        }
-      ) mountable;
+      lib.mkImageMediaOverride (
+        lib.mapAttrs' (
+          dataset: opts:
+          lib.nameValuePair opts.mount {
+            device = dataset;
+            fsType = "zfs";
+          }
+        ) mountable
+      );
   };
 }
diff --git a/nixos/modules/virtualisation/proxmox-image.nix b/nixos/modules/virtualisation/proxmox-image.nix
index cb83a9e5ef29..25aa3aee93c7 100644
--- a/nixos/modules/virtualisation/proxmox-image.nix
+++ b/nixos/modules/virtualisation/proxmox-image.nix
@@ -306,7 +306,13 @@ with lib;
           ''
             ${vma}/bin/vma create "${config.image.baseName}.vma" \
               -c ${
-                cfgFile "qemu-server.conf" (cfg.qemuConf // cfg.qemuExtraConf)
+                cfgFile "qemu-server.conf" (
+                  (builtins.removeAttrs cfg.qemuConf [ "diskSize" ])
+                  // {
+                    inherit (config.virtualisation) diskSize;
+                  }
+                  // cfg.qemuExtraConf
+                )
               }/qemu-server.conf drive-virtio0=$diskImage
             rm $diskImage
             ${pkgs.zstd}/bin/zstd "${config.image.baseName}.vma"
@@ -346,14 +352,16 @@ with lib;
         ];
       };
 
-      fileSystems."/" = {
-        device = "/dev/disk/by-label/nixos";
-        autoResize = true;
-        fsType = "ext4";
-      };
-      fileSystems."/boot" = lib.mkIf hasBootPartition {
-        device = "/dev/disk/by-label/ESP";
-        fsType = "vfat";
+      fileSystems = lib.mkImageMediaOverride {
+        "/" = {
+          device = "/dev/disk/by-label/nixos";
+          autoResize = true;
+          fsType = "ext4";
+        };
+        "/boot" = lib.mkIf hasBootPartition {
+          device = "/dev/disk/by-label/ESP";
+          fsType = "vfat";
+        };
       };
 
       networking = mkIf cfg.cloudInit.enable {
diff --git a/nixos/modules/virtualisation/virtualbox-image.nix b/nixos/modules/virtualisation/virtualbox-image.nix
index 26633731f647..17dfa17cfbbb 100644
--- a/nixos/modules/virtualisation/virtualbox-image.nix
+++ b/nixos/modules/virtualisation/virtualbox-image.nix
@@ -275,7 +275,7 @@ in
     };
 
     fileSystems =
-      {
+      lib.mkImageMediaOverride {
         "/" = {
           device = "/dev/disk/by-label/nixos";
           autoResize = true;
diff --git a/nixos/modules/virtualisation/vmware-image.nix b/nixos/modules/virtualisation/vmware-image.nix
index 6eebc6910ff0..f44c4b5bae07 100644
--- a/nixos/modules/virtualisation/vmware-image.nix
+++ b/nixos/modules/virtualisation/vmware-image.nix
@@ -83,15 +83,17 @@ in
       inherit config lib pkgs;
     };
 
-    fileSystems."/" = {
-      device = "/dev/disk/by-label/nixos";
-      autoResize = true;
-      fsType = "ext4";
-    };
+    fileSystems = lib.mkImageMediaOverride {
+      "/" = {
+        device = "/dev/disk/by-label/nixos";
+        autoResize = true;
+        fsType = "ext4";
+      };
 
-    fileSystems."/boot" = {
-      device = "/dev/disk/by-label/ESP";
-      fsType = "vfat";
+      "/boot" = {
+        device = "/dev/disk/by-label/ESP";
+        fsType = "vfat";
+      };
     };
 
     boot.growPartition = true;