diff --git a/install.sh b/install.sh
old mode 100644
new mode 100755
index fcd144b..f3767b5
--- a/install.sh
+++ b/install.sh
@@ -5,5 +5,23 @@
 
 # FUNCTIONS
 
+function halt_on_error {
+	>&2 echo "ERROR: $1"
+	exit ${2:-1}
+}
+
+function assert_root {
+    [ "$(id -u)" -ne 0 ] && halt_on_error 'root privilege required!'
+}
+
+function assert_proxmox {
+	grep -q ^ID=debian /etc/os-release || halt_on_error 'distro debian required!' 2
+	command -v pct >/dev/null || halt_on_error 'command `pct` not found!' 3
+}
+
 # MAIN
 
+set Eue
+assert_root
+assert_proxmox
+echo OK