Merge r1295 from branches/ganeti/ganeti-1.2

Clarify cluster IP requirement.

Reviewed-by: iustinp

doc/install.sgml

@@ -698,7 +698,9 @@ gnt-cluster init <replaceable>CLUSTERNAME</replaceable>
         nodes names for a multi-node cluster. In general the best
         choice is to have a unique name for a cluster, even if it
         consists of only one machine, as you will be able to expand it
-        later without any problems.
+        later without any problems. Please note that the hostname used
+        for this must resolve to an IP address reserved exclusively
+        for this purpose.
       </para>
 
       <para>

man/gnt-cluster.sgml

@@ -228,8 +228,8 @@
         Note that the <replaceable>clustername</replaceable> is not
         any random name. It has to be resolvable to an IP address
         using DNS, and it is best if you give the fully-qualified
-        domain name. Also it is advisable to reserve a per-cluster
-        unique name, and not try to reuse one of the nodes' names.
+        domain name. This hostname must resolve to an IP address
+        reserved exclusively for this purpose.
       </para>
 
       <para>