xl.pod.1: add a note about autoballoon and dom0_mem

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

docs/man/xl.pod.1

@@ -32,19 +32,35 @@ each of those subcommands.
 
 =head1 NOTES
 
+=over 4
+
+=item start the script B</etc/init.d/xencommons> at boot time
+
 Most B<xl> operations rely upon B<xenstored> and B<xenconsoled>: make
 sure you start the script B</etc/init.d/xencommons> at boot time to
 initialize all the daemons needed by B<xl>.
 
+=item setup a B<xenbr0> bridge in dom0
+
 In the most common network configuration, you need to setup a bridge in dom0
 named B<xenbr0> in order to have a working network in the guest domains.
 Please refer to the documentation of your Linux distribution to know how to
 setup the bridge.
 
+=item B<autoballoon>
+
+If you specify the amount of memory dom0 has, passing B<dom0_mem> to
+Xen, it is highly reccomended to disable B<autoballoon>. Edit
+B</etc/xen/xl.conf> and set it to 0.
+
+=item run xl as B<root>
+
 Most B<xl> commands require root privileges to run due to the
 communications channels used to talk to the hypervisor.  Running as
 non root will return an error.
 
+=back
+
 =head1 GLOBAL OPTIONS
 
 Some global options are always available: