diff --git a/xCAT-test/bats/diskless_flat_vmothersetting_machine.bats b/xCAT-test/bats/diskless_flat_vmothersetting_machine.bats
new file mode 100644
index 000000000..c0e37b165
--- /dev/null
+++ b/xCAT-test/bats/diskless_flat_vmothersetting_machine.bats
@@ -0,0 +1,85 @@
+#!/usr/bin/env bats
+#
+# reg_linux_diskless_installation_flat corrupts the KVM machine type of the compute node, checks
+# that the node fails to boot, and then restores it. The restore reads a machine type from a
+# ladder that names ppc64 and x86_64 only, so on any other architecture it writes an empty
+# vmothersetting and the check after it fails.
+#
+# The two commands are lifted out of the case file and RUN, with lsdef and chdef shadowed, so
+# the assertions read the value the case would write. The extraction fails the test when it
+# stops matching, so a rewrite fails loudly instead of covering nothing.
+
+load 'helpers/shell_source'
+
+setup()
+{
+    CASE="$(repo_path 'xCAT-test/autotest/testcase/installation/reg_linux_diskless_installation_flat')"
+    [ -r "$CASE" ] || skip "$CASE is required"
+    export CASE
+}
+
+# The command that restores the machine type, and the one that removes it again afterwards.
+restore_command()
+{
+    extract_first_matching_line "$CASE" \
+        '^cmd:.*str2="machine:invalid".*chdef [$][$]CN vmothersetting=[$]str5'
+}
+
+remove_command()
+{
+    extract_first_matching_line "$CASE" \
+        '^cmd:.*str2=";".*~ "ppc64".*chdef [$][$]CN vmothersetting='
+}
+
+# Render one command the way xcattest does, then run it with lsdef and chdef shadowed. bash
+# resolves a function ahead of PATH, so the case's own backticks read the stub.
+#
+# Sets OUT to everything the command printed and WRITTEN to the value it gave chdef.
+run_case_command()
+{
+    local cmd="$1" arch="$2" lsdef_value="$3"
+
+    cmd="${cmd#cmd:}"
+    cmd="${cmd//__GETNODEATTR(\$\$CN,arch)__/$arch}"
+    cmd="${cmd//__GETNODEATTR(\$\$CN,mgt)__/kvm}"
+    cmd="${cmd//\$\$CN/cn1}"
+
+    OUT="$(bash -c "lsdef() { echo '    vmothersetting=$lsdef_value'; }
+chdef() { echo \"CHDEF:\$*\"; }
+$cmd" 2>&1)" || true
+    WRITTEN="$(sed -n 's/^CHDEF:cn1 vmothersetting=//p' <<<"$OUT")"
+}
+
+# The machine type each architecture must end up with. riscv64 guests run the qemu "virt"
+# machine; kvm.pm sets it in guest_arch_profile.
+assert_arch()
+{
+    local arch="$1" machine="$2" restore remove
+
+    restore="$(restore_command)"
+    remove="$(remove_command)"
+
+    run_case_command "$restore" "$arch" 'machine:invalid'
+    [ -n "$WRITTEN" ]
+    [[ "$WRITTEN" == *machine:* ]]
+    [[ "$WRITTEN" == *"$machine"* ]]
+
+    # The check the case runs straight after the restore.
+    [[ "$WRITTEN" == *machine* ]]
+
+    # The remove path reads the same ladder; it must not die on an empty str3.
+    run_case_command "$remove" "$arch" "machine:$machine"
+    [ "$(grep -c 'unary operator expected' <<<"$OUT")" -eq 0 ]
+}
+
+@test "ppc64le: the restore writes the machine type, and the remove path compares two strings" {
+    assert_arch ppc64le pseries
+}
+
+@test "x86_64: the restore writes the machine type, and the remove path compares two strings" {
+    assert_arch x86_64 pc
+}
+
+@test "riscv64: the restore writes the machine type, and the remove path compares two strings" {
+    assert_arch riscv64 virt
+}
diff --git a/xCAT-test/unit/diskless_flat_vmothersetting_machine.t b/xCAT-test/unit/diskless_flat_vmothersetting_machine.t
deleted file mode 100644
index 1f47f72a0..000000000
--- a/xCAT-test/unit/diskless_flat_vmothersetting_machine.t
+++ /dev/null
@@ -1,72 +0,0 @@
-#!/usr/bin/perl
-# reg_linux_diskless_installation_flat corrupts the KVM machine type of the compute node, checks
-# that the node fails to boot, and then restores it. The restore reads a machine type from a ladder
-# that names ppc64 and x86_64 only, so on any other architecture it writes an empty vmothersetting
-# and the check after it fails.
-#
-# The two commands are lifted out of the case file and RUN, with lsdef and chdef shadowed, so the
-# assertions read the value the case would write. die when an extraction stops matching, so a
-# rewrite fails loudly instead of covering nothing.
-use strict;
-use warnings;
-use Test::More;
-use File::Basename qw(dirname);
-
-my $case = dirname(__FILE__)
-    . '/../autotest/testcase/installation/reg_linux_diskless_installation_flat';
-open my $fh, '<', $case or die("cannot read $case: $!");
-my @lines = <$fh>;
-close $fh;
-
-# The command that restores the machine type, and the one that removes it again afterwards.
-my ($restore) = grep { /^cmd:.*str2="machine:invalid".*chdef \$\$CN vmothersetting=\$str5/ } @lines;
-my ($remove)  = grep { /^cmd:.*str2=";".*=~ "ppc64".*chdef \$\$CN vmothersetting=/ } @lines;
-die('cannot find the command that restores the machine type') unless $restore;
-die('cannot find the command that removes the machine type')  unless $remove;
-
-# Render one command the way xcattest does, then run it with lsdef and chdef shadowed. bash
-# resolves a function ahead of PATH, so the case's own backticks read the stub.
-my $run = sub {
-    my ($cmd, $arch, $lsdef_value) = @_;
-    $cmd =~ s/^cmd://;
-    $cmd =~ s/__GETNODEATTR\(\$\$CN,arch\)__/$arch/g;
-    $cmd =~ s/__GETNODEATTR\(\$\$CN,mgt\)__/kvm/g;
-    $cmd =~ s/\$\$CN/cn1/g;
-    my $prelude = "lsdef() { echo '    vmothersetting=$lsdef_value'; }\n"
-                . "chdef() { echo \"CHDEF:\$*\"; }\n";
-    my $out = qx{bash -c @{[ quotemeta_cmd($prelude . $cmd) ]} 2>&1};
-    my ($written) = $out =~ /^CHDEF:cn1 vmothersetting=(.*)$/m;
-    return { out => $out, written => $written, rc => $? >> 8 };
-};
-
-sub quotemeta_cmd { my ($s) = @_; $s =~ s/'/'\\''/g; return "'$s'" }
-
-# The machine type each architecture must end up with. riscv64 guests run the qemu "virt" machine;
-# kvm.pm sets it in guest_arch_profile.
-my %machine = (
-    ppc64le => 'pseries',
-    x86_64  => 'pc',
-    riscv64 => 'virt',
-);
-
-for my $arch (sort keys %machine) {
-    my $r = $run->($restore, $arch, 'machine:invalid');
-    ok( defined $r->{written} && length $r->{written},
-        "$arch: the restore writes a vmothersetting rather than an empty one" );
-    like( $r->{written} // '', qr/\bmachine:/,
-        "$arch: the restored vmothersetting names a machine type" );
-    like( $r->{written} // '', qr/\Q$machine{$arch}\E/,
-        "$arch: the restored machine type is $machine{$arch}" );
-
-    # The check the case runs straight after the restore.
-    my $keeps_machine = ( $r->{written} // '' ) =~ /machine/ ? 0 : 1;
-    is( $keeps_machine, 0,
-        "$arch: the check after the restore, 'vmothersetting contains machine', passes" );
-
-    # The remove path reads the same ladder; it must not die on an empty str3.
-    my $d = $run->($remove, $arch, "machine:$machine{$arch}");
-    unlike( $d->{out}, qr/unary operator expected/,
-        "$arch: the remove path compares two defined strings" );
-}
-
-done_testing();