Re: [Xen-users] amd64 system only seeing 3.5gb instead of 4gb of memory

[Rafał Kupka <rkupka+Listy.Xen@xxxxxxxxxxxxx>]

On Fri, Jun 15, 2007 at 03:38:24PM +1000, James Harper wrote:
Hello,

> I've just had a server upgraded to 4gb of memory... BIOS reports 4gb of
> memory but xen only sees 3.5gb (3583mb)

What about plain linux kernel? How much it see?

> I was under the impression that an amd64 server should be able to see
> well over 4gb of memory. I believe that PCI space and other stuff gets
> mapped to the very top of memory... is there some setting somewhere that
> I might need to set to get that .5gb mapped to somewhere visible?

Only BIOS can do that. Search for "PCI memory hole" or some memory
remapping option (maybe with values: continuous/discontig).

By "amd64" you mean AMD processor[1]? Some older Inter chipsets cannot
remap RAM above 4G.

If problem persists please post e820 memory map from xm dmesg (that
lines after "(XEN) Physical RAM map:") and from plain linux kernel.

Kupson
[1] Debian uses amd64 as arch name, instead of x86-64.
-- 
Great software without the knowledge to run it is pretty useless.
(Linux Gazette #1)

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users