DLPX-88573 Perform deferred upgrade prior to VDB downtime for FULL up…

…grade (#742)

upgrade/upgrade-scripts/execute

@@ -604,7 +604,13 @@ if [[ -f "$UPDATE_DIR/upgrade.properties" ]]; then
 	source_upgrade_properties
 fi
 
-if [[ -n "$opt_f" ]] || [[ "$UPGRADE_TYPE" == "FULL" ]]; then
+#
+# On versions 18.0 and greater, we don't issue the reboot. Rather,
+# we restart the delphix services, and the reboot will be issued by
+# the virtualization service as it starts up.
+#
+if { [[ -n "$opt_f" ]] || [[ "$UPGRADE_TYPE" == "FULL" ]]; } &&
+	compare_versions "$CURRENT_VERSION" lt "18.0.0.0-0"; then
 	post_alert "reboot"
 	exec systemctl reboot || die "failed to reboot"
 else