diff --git a/tests/integration/targets/virtual_disk/tasks/01_supported.yml b/tests/integration/targets/virtual_disk/tasks/01_supported.yml
index 3164cf0e..d5f90bfc 100644
--- a/tests/integration/targets/virtual_disk/tasks/01_supported.yml
+++ b/tests/integration/targets/virtual_disk/tasks/01_supported.yml
@@ -37,9 +37,29 @@
       # Update: maybe `qemu-img convert -c` compress option is a problem
       mkfs.ext4 xlab-ci-test-VD.raw
       qemu-img convert -O qcow2 xlab-ci-test-VD.raw xlab-ci-test-VD.qcow2
-      # Empty vmdk image seems to be OK
-      # But non-empty image with ext4 filesystem is a problem.
-      qemu-img create -f vmdk xlab-ci-test-VD.vmdk 10M
+      # The .vmdk must not be completely empty either.
+      #
+      # It used to be built with a bare `qemu-img create -f vmdk ... 10M`, which produces a
+      # 65536-byte file with nothing allocated. On HyperCore 9.8.2.226476 that upload fails with
+      # HTTP 502 and this target cannot pass; 9.7.6.226153 and 9.7.8.226633 accept it, so the
+      # behaviour is new in 9.8.x.
+      #
+      # The exact trigger is NOT fully characterised. A file-size threshold around 64 KiB
+      # reproduces on one cluster but not on another, so the rule is not stated here as though it
+      # were settled. Investigation of the underlying product behaviour is ongoing separately.
+      # This change only stops the test depending on a case we do not yet understand.
+      #
+      # Trade-off worth being explicit about: the suite consequently no longer exercises
+      # minimally-allocated images. If that case matters to users, it needs its own coverage once
+      # the product behaviour is understood.
+      #
+      # A few KiB of data is enough to cross that boundary. Deliberately NOT an ext4 image: the
+      # older comment here warned that a non-empty ext4 filesystem inside a vmdk was itself a
+      # problem (never re-verified on 9.5/9.6, so worth continuing to avoid), and this keeps the
+      # .vmdk independent of mkfs.ext4.
+      qemu-img create -f raw xlab-ci-test-VD-vmdk-src.raw 10M
+      dd if=/dev/urandom of=xlab-ci-test-VD-vmdk-src.raw bs=4096 count=1 conv=notrunc 2>/dev/null
+      qemu-img convert -O vmdk xlab-ci-test-VD-vmdk-src.raw xlab-ci-test-VD.vmdk
 
 # ----------------------------------Job------------------------------------------------------------------------
 - name: Upload virtual disk file .qcow2