diff --git a/xCAT-server/share/xcat/netboot/sles/genimage b/xCAT-server/share/xcat/netboot/sles/genimage
index df9793d52..be9285703 100755
--- a/xCAT-server/share/xcat/netboot/sles/genimage
+++ b/xCAT-server/share/xcat/netboot/sles/genimage
@@ -437,14 +437,14 @@ if($mode eq "statelite") {
 #otherwise got kernal panic when installing 
 #sometimes, the proc fs is not mounted, so one warning/error message will display,
 #and I add one check point here.
-my $MTABFD;
-open MTABFD, "/etc/mtab";
-my @lines = <MTABFD>;
-close MTABFD;
+my $MFD;
+open MFD, "/proc/mounts";
+my @lines = <MFD>;
+close MFD;
 
 my $ret = grep m{$rootimg_dir/proc}, @lines;
 if($ret > 0) {
-    system("umount $rootimg_dir/proc");
+    system("umount -l $rootimg_dir/proc");
 }
 
 mkinitrd();