From 8f990792fcf6e6f1c1e9b751d1a489ca6b39f55f Mon Sep 17 00:00:00 2001
From: Xin LI <delphij@FreeBSD.org>
Date: Wed, 15 Apr 2015 21:48:06 +0000
Subject: [PATCH] Verify if the saved hostid is still the same and update if it
 was changed.

Sponsored by:	iXsystems, Inc.
Obtained from:	FreeNAS (trueos commit 0abb740)
---
 etc/rc.d/hostid_save | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/etc/rc.d/hostid_save b/etc/rc.d/hostid_save
index fca0521e8b24..9741aec09f82 100755
--- a/etc/rc.d/hostid_save
+++ b/etc/rc.d/hostid_save
@@ -16,12 +16,19 @@ rcvar="hostid_enable"
 
 hostid_save()
 {
-	if [ ! -r ${hostid_file} ]; then
-		$SYSCTL_N kern.hostuuid > ${hostid_file}
-		if [ $? -ne 0 ]; then
-			warn "could not store hostuuid in ${hostid_file}."
+	current_hostid=`$SYSCTL_N kern.hostuuid`
+
+	if [ -r ${hostid_file} ]; then
+		read saved_hostid < ${hostid_file}
+		if [ ${saved_hostid} = ${current_hostid} ]; then
+			exit 0
 		fi
 	fi
+
+	echo ${current_hostid} > ${hostid_file}
+	if [ $? -ne 0 ]; then
+		warn "could not store hostuuid in ${hostid_file}."
+	fi
 }
 
 load_rc_config $name