Dual Opterons don't see all memory

[Paul Schmehl]

--On Thursday, September 27, 2007 06:35:53 +0100 Matthew Seaman 
<m.seaman at infracaninophile.co.uk> wrote:

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> Erich Dollansky wrote:
>
>> Paul Schmehl wrote:
>>> --On September 26, 2007 9:06:57 PM -0700 Eric Osterweil
>>> <eoster at CS.UCLA.EDU> wrote:
>>>
>>>> On Sep 26, 2007, at 8:57 PM, Erich Dollansky wrote:
>>>>
>>>>> Eric Osterweil wrote:
>>>>>
>>>>>> make use of it's 6GB of memory, and FreeBSD can only see about 4GB
>>>>>> of it.
>>>>>> Can anyone help me figure out how to make use of the missing GB?
>>>>>> FreeBSD 6.2-RELEASE #0: Fri Jan 12 11:05:30 UTC 2007
>>>>>
>>>>> this looks like a 32 bit binary to me.
>>>>>
>>>>> You either need a 64 bit binary or you need to enable PAE.
>>>>>
>>>>> Just build a custom kernel for 64 bits.
>>>>>
>>>>
>>>> Ahh... To do this, do I just specify the CPUTYPE in the /etc/make.conf
>>>> as:
>>>> CPUTYPE=amd64
>>>> ?
>>>>
>>> No.  Add options SMP to GENERIC or use the SMP conf file that's
>>> already there (and includes GENERIC).  Then recompile the kernel per
>>> the handbook.
>>>
>> he still has to set the CPU type also in this config file to amd64.
>
> If the OP has installed FreeBSD i386 then changing the CPU type in
> /etc/make.conf won't magically get him FreeBSD amd64 --- it will just
> get him FreeBSD i386 optimized for AMD processors running in 32bit
> mode.
>
> As far as I know, there is no simple way to start with a 32-bit
> system and the FreeBSD sources and recompile and reinstall everything
> into a 64-bit system.  (Although the opposite direction is apparently
> possible on 7-CURRENT, but it's a guru-only level of difficulty.)
>
> The best and most effective answer here is to start by downloading
> an amd64 installation CD and redo the whole thing from scratch.
>
Thanks, Matthew.  Guess I should stop assuming that the OP used the right 
distro to begin with....

-- 
Paul Schmehl (pauls at utdallas.edu)
Senior Information Security Analyst
The University of Texas at Dallas
http://www.utdallas.edu/ir/security/