[Fedora-xen] Re: Heads-up: Requiring PAE for running Xen

[Lamont R. Peterson]

On Wednesday 17 May 2006 05:57pm, Daniel P. Berrange wrote:
> On Wed, May 17, 2006 at 11:42:43PM +0200, Axel Thimm wrote:
[snip]
> > How do I know if my laptop if affected? :)

Do you have a 32bit laptop that can take more than 4GB of RAM?  Not likely.  
Because of the fact that most laptops are not designed to plug that much RAM 
(most today top out at 2GB, even), it seems that most laptop makers do not 
use chips that can support PAE.

> Take a look at the 'flags' field in /proc/cpuinfo - look for a flag
> called 'pae' in it - if your CPU is a Pentium Mobile the chances are
> you won't see the 'pae' flag there.
>
> For example on my laptop which dosn't have PAE:
>
>   [berrange at localhost ~]$ grep pae /proc/cpuinfo
>   [berrange at localhost ~]$
>
> While on my desktop, which does have PAE:
>
>   [berrange at camden berrange]$  grep pae /proc/cpuinfo
>   flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
> mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm

I have on rare occasion, seen some Intel chips list pae in their flage even 
though the chip doesn't support it.  I have also heard (but seen it myself) 
of some boards built for Intel chips which could support pae, but the board's 
memory controller or number of slots or BIOS (or whatever) prevents it from 
being used (like, not being able to plug in more than 4GB anyway).
-- 
Lamont R. Peterson <lamont at gurulabs.com>
Senior Instructor
Guru Labs, L.C. [ http://www.GuruLabs.com/ ]
GPG Key fingerprint: F98C E31A 5C4C 834A BCAB  8CB3 F980 6C97 DC0D D409
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/fedora-xen/attachments/20060517/09b721f9/attachment.sig>