release-testing: Further mitigate LVM race conditions by using xen-delete-image

NEWS.markdown

@@ -50,8 +50,11 @@ Test Suite
 ----------
 
 * release-testing:
-  + Use per-test-unique host names. Avoids race conditions with
-    immediately re-used LVs.
+  + Mitigate race conditions with immediately re-used LVs:
+    - Use per-test-unique host names.
+    - Delete potential old images by testing xen-delete-image before
+      calling xen-create-image. Add sync and sleep calls inbetween
+      those two commands, too.
   + Use "set -e" instead of "|| break".
   + Declare testability in distributions.conf instead of hardcoding
     it. Mark buster and bullseye as not testable, too, for now.

examples/release-testing

@@ -5,5 +5,8 @@ set -e
 exec 2>&1 | tee xen-tools-release-testing.log
 
 for dist in $(awk '!/^#|^$|dont-test/ {print $1}' /etc/xen-tools/distributions.conf); do
-    xen-create-image --dist $dist --hostname "xen-tools-release-testing-$dist" --force --verbose "$@"
+    xen-delete-image --verbose --hostname "xen-tools-release-testing-$dist"
+    sync
+    sleep 5
+    xen-create-image --verbose --hostname "xen-tools-release-testing-$dist" --dist $dist --force "$@"
 done