Re: [Hampshire] How to tell how much memory?

Victor Churchill wrote:
> On 14/07/07, Jonathan Hudson <jh+hlug@???> wrote:
>> On Sat, 14 Jul 2007 18:18:37 +0100
>> "Victor Churchill" <victorchurchill@???> wrote:
>> > But ...
>> > memtest says it is testing 768 MB.
>> > 'top' says 769500 K.
>> > System Monitor 751.5 MB.
>> > /proc/meminfo 769500 .
>> > dmesg : 762904K/786368K total.
>> >
>> > All I can think of is that one of my mem sticks is faulty and thinks
>> > it is 512 MB, and reports this, but in fact has 'lost' half of it
>> > (address line stuck?)
>> >
>> You have a kernel build with the (old) <1G memory model. In this mode
>> Linux does only see 768K.
>>
>> You need to build the kernel with 1+3 or 2+2 (mapping of VM between
>> kernel and user space) or whatever its called.
>>
>> I expect the hardware is fine.
>>
>> -jonathan
>>
>
> OK ... but rather surprising. This box is running feisty 7.04, and
> uname -a gives
> 2.6.20-16-generic #2 SMP Thu Jun 7 19:00:28 UTC 2007 x86-64 Gnu/Linux
>
> So not an 'old' kernel ... but maybe the default build uses the 'old'
> memory model.
> Not sure if I'm up for doing a kernel build atm: it's a long time
> since I last tried doing that.
>
> Maybe I should look over on Ubuntu Forums to see if there's any info
> on getting an install image configured for 1GB+ ... [1]
>
> (And Vic's suggestion supports what you say about the h/w : dmidecode
> reports 2*512 MB sticks. Thanks!)
>
> Thanks also Alan for lshw suggestion; that also says I have 2*512MB.
>
> Video GPU is an onboard NVidia GeForce 6100 NForce 405 which Ububtu's
> NVidia X Server Settings says has 512 MB so I shouldn't imagine it's
> stealing my main memory as well..
>
> [1] might go for a 32-bit distro this time: the current 64-bit system
> I am running does not seem to be showing much benefit, and seems a bit
> flakey. But that's another thread...
>
I am running feisty 7.04 with 2G with out a problem using the default
kernel uname -a give:

2.6.20-16-generic #2 SMP Thu Jun 7 20:19:32 UTC 2007 i686 GNU/Linux

so I doubt it is a kernel problem. Although I am using 32-bit kernel
rather than the 64-bit.

Have you checked the kernel boot option in grub. I seem to remember it
is possible to manually tell the kernel how much memory you have.

Kevin.