4 files changed, 12 insertions, 12 deletions
diff --git a/nixos/lib/make-disk-image.nix b/nixos/lib/make-disk-image.nix
index 5e86ea479d51..9364aab32770 100644
--- a/nixos/lib/make-disk-image.nix
+++ b/nixos/lib/make-disk-image.nix
@@ -39,7 +39,7 @@
 
 , name ? "nixos-disk-image"
 
-, # Disk image format, one of qcow2, qcow2-compressed, vpc, raw.
+, # Disk image format, one of qcow2, qcow2-compressed, vdi, vpc, raw.
   format ? "raw"
 }:
 
@@ -57,6 +57,7 @@ let format' = format; in let
 
   filename = "nixos." + {
     qcow2 = "qcow2";
+    vdi   = "vdi";
     vpc   = "vhd";
     raw   = "img";
   }.${format};
diff --git a/nixos/lib/make-iso9660-image.nix b/nixos/lib/make-iso9660-image.nix
index 0f3f2b5b5234..12a6cf649966 100644
--- a/nixos/lib/make-iso9660-image.nix
+++ b/nixos/lib/make-iso9660-image.nix
@@ -34,8 +34,8 @@
 , # The path (outside the ISO file system) of the isohybrid-mbr image.
   isohybridMbrImage ? ""
 
-, # Whether to compress the resulting ISO image with bzip2.
-  compressImage ? false
+, # Whether to compress the resulting ISO image with zstd.
+  compressImage ? false, zstd
 
 , # The volume ID.
   volumeID ? ""
@@ -48,7 +48,7 @@ assert usbBootable -> isohybridMbrImage != "";
 stdenv.mkDerivation {
   name = isoName;
   builder = ./make-iso9660-image.sh;
-  buildInputs = [ xorriso syslinux ];
+  buildInputs = [ xorriso syslinux zstd ];
 
   inherit isoName bootable bootImage compressImage volumeID efiBootImage efiBootable isohybridMbrImage usbBootable;
 
diff --git a/nixos/lib/make-iso9660-image.sh b/nixos/lib/make-iso9660-image.sh
index d4633d2c8d16..d64fe9a365e7 100644
--- a/nixos/lib/make-iso9660-image.sh
+++ b/nixos/lib/make-iso9660-image.sh
@@ -129,9 +129,14 @@ fi
 
 if test -n "$compressImage"; then
     echo "Compressing image..."
-    bzip2 $out/iso/$isoName
+    zstd -T$NIX_BUILD_CORES --rm $out/iso/$isoName
 fi
 
 mkdir -p $out/nix-support
 echo $system > $out/nix-support/system
-echo "file iso $out/iso/$isoName" >> $out/nix-support/hydra-build-products
+
+if test -n "$compressImage"; then
+    echo "file iso $out/iso/$isoName.zst" >> $out/nix-support/hydra-build-products
+else
+    echo "file iso $out/iso/$isoName" >> $out/nix-support/hydra-build-products
+fi
diff --git a/nixos/lib/test-driver/test-driver.py b/nixos/lib/test-driver/test-driver.py
index bf46d0df97f9..e7b05968b079 100644
--- a/nixos/lib/test-driver/test-driver.py
+++ b/nixos/lib/test-driver/test-driver.py
@@ -598,11 +598,8 @@ class Machine:
                 shutil.copytree(host_src, host_intermediate)
             else:
                 shutil.copy(host_src, host_intermediate)
-            self.succeed("sync")
             self.succeed(make_command(["mkdir", "-p", vm_target.parent]))
             self.succeed(make_command(["cp", "-r", vm_intermediate, vm_target]))
-        # Make sure the cleanup is synced into VM
-        self.succeed("sync")
 
     def copy_from_vm(self, source: str, target_dir: str = "") -> None:
         """Copy a file from the VM (specified by an in-VM source path) to a path
@@ -620,7 +617,6 @@ class Machine:
             # Copy the file to the shared directory inside VM
             self.succeed(make_command(["mkdir", "-p", vm_shared_temp]))
             self.succeed(make_command(["cp", "-r", vm_src, vm_intermediate]))
-            self.succeed("sync")
             abs_target = out_dir / target_dir / vm_src.name
             abs_target.parent.mkdir(exist_ok=True, parents=True)
             # Copy the file from the shared directory outside VM
@@ -628,8 +624,6 @@ class Machine:
                 shutil.copytree(intermediate, abs_target)
             else:
                 shutil.copy(intermediate, abs_target)
-        # Make sure the cleanup is synced into VM
-        self.succeed("sync")
 
     def dump_tty_contents(self, tty: str) -> None:
         """Debugging: Dump the contents of the TTY<n>