+#check access
+if dd if="$DISK" of=/dev/null bs=1 count=1 >/dev/null 2>&1; then
+ vtdebug "root permission check ok ..."
+else
+ vterr "Failed to access $DISK, maybe root privilege is needed!"
+ echo ''
+ exit 1
+fi
+
+
+#check tmp_mnt directory
+if [ -d ./tmp_mnt ]; then
+ vtdebug "There is a tmp_mnt directory, now delete it."
+ umount ./tmp_mnt >/dev/null 2>&1
+ rm -rf ./tmp_mnt
+ if [ -d ./tmp_mnt ]; then
+ vterr "tmp_mnt directory exits, please delete it first."
+ exit 1
+ fi
+fi
+