copr-builders: allow using /dev/vdd for swap, too

roles/copr/backend/files/provision/files/enable-swap.sh

@@ -6,14 +6,24 @@ set -e
 part_suffix=p
 swap_device=
 if test -e /dev/xvda1 && test -e /dev/nvme0n1; then
+    # AWS aarch64 machine.  We use separate volume allocation as the default
+    # root disk in our instance type is too small.
     swap_device=/dev/nvme0n1
 elif test -e /dev/nvme1n1; then
-    # AWS machine
+    # AWS x86_64 machine.  There's >= 400G space on the default volume in our
+    # instance type.
     swap_device=/dev/nvme1n1
-elif test -e /dev/vdb; then
-    # libvirt machine, and IBM Cloud s390x
-    swap_device=/dev/vdb
-    part_suffix=
+else
+    # LibVirt (on-premise) machine, or the IBM Cloud machine.  Find the "large"
+    # volume, that one will be used.
+    for vol in /dev/vdb /dev/vdd; do
+       mount | grep $vol && continue
+       size=$(blockdev --getsize64 "$vol")
+       test "$size" -le 150000000000 && continue
+       swap_device=$vol
+       part_suffix=
+       break
+    done
 fi
 
 test -n "$swap_device"