diff --git a/playbooks/vhost_update_reboot.yml b/playbooks/vhost_update_reboot.yml
index 991c3297be..0d60cb2189 100644
--- a/playbooks/vhost_update_reboot.yml
+++ b/playbooks/vhost_update_reboot.yml
@@ -1,3 +1,11 @@
 ---
+# Note that someone probably wants to run:
+# ansible -m shell -a 'dnf --refresh -y update; rkhunter --propupd' all:!copr*:!openqa*:!ocp*:!worker*'
+# ...during an outage. Note that doing more than one vmhost at once isn't
+# easily safe, because some vmhost will want another to be up while they reboot.
+# Also:
+# ansible -m shell -a 'dnf --refresh -y update; rkhunter --propupd' staging:!copr*:!openqa*:!ocp*:!worker*'
+# could be used for staging, but it's not that big.
+
 - import_playbook: /srv/web/infra/ansible/playbooks/vhost_update.yml
 - import_playbook: /srv/web/infra/ansible/playbooks/vhost_reboot.yml
diff --git a/scripts/updates-uptime-cmd.py b/scripts/updates-uptime-cmd.py
index 8b26719152..8047753ab0 100755
--- a/scripts/updates-uptime-cmd.py
+++ b/scripts/updates-uptime-cmd.py
@@ -351,9 +351,9 @@ if cmd in ("diff", "diff-u"):
   fn1 = fname + '.' + cmp
   fn2 = fname
   data1 = fname2lines(fn1)
-  if len(sys.argv) >= 2 and sys.argv[1] in backups:
+  if len(sys.argv) >= 3 and sys.argv[2] in backups:
     # Doing a diff. between two backups...
-    fn2 = fname + '.' + sys.argv[1]
+    fn2 = fname + '.' + sys.argv[2]
   data2 = fname2lines(fn2)
   print("diff %s %s" % (fn1, fn2), file=sys.stderr)
   _max_update(data1)