diff --git a/docs/install.sgml b/docs/install.sgml index 134f28c1bbb1fb4e84e8731865d910e49fad85bd..9940c3335c4d7ccf2622e21c501af7564b9bf9c2 100644 --- a/docs/install.sgml +++ b/docs/install.sgml @@ -192,6 +192,58 @@ </para> </formalpara> + <sect3> + <title>Xen settings</title> + + <para> + It's recommended that dom0 is restricted to a low amount of + memory (<constant>512MiB</constant> is reasonable) and that + memory ballooning is disabled in the file + <filename>/etc/xen/xend-config.sxp</filename> by setting the + value <literal>dom0-min-mem</literal> to + <constant>0</constant>, like this: + <computeroutput>(dom0-min-mem 0)</computeroutput> + </para> + + <para> + For optimum performance when running both CPU and I/O + intensive instances, it's also recommended that the dom0 is + restricted to one CPU only, for example by booting with the + kernel parameter <literal>nosmp</literal>. + </para> + + <formalpara> + <title>Debian</title> + <para> + Besides the balloning change which you need to set in + <filename>/etc/xen/xend-config.sxp</filename>, you need to + set the memory and nosmp parameters in the file + <filename>/boot/grub/menu.lst</filename>. You need to + modify the variable <literal>xenhopt</literal> to add + <userinput>dom0_mem=512M</userinput> like this: +<screen> +## Xen hypervisor options to use with the default Xen boot option +# xenhopt=dom0_mem=512M +</screen> + and the <literal>xenkopt</literal> needs to include the + <userinput>nosmp</userinput> option like this: +<screen> +## Xen Linux kernel options to use with the default Xen boot option +# xenkopt=nosmp +</screen> + + Any existing parameters can be left in place: it's ok to + have <computeroutput>xenkopt=console=tty0 + nosmp</computeroutput>, for example. After modifying the + files, you need to run: +<screen> +/sbin/update-grub +</screen> + </para> + </formalpara> + + </sect3> + <sect3> <title>Selecting the instance kernel</title>