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1 Gb memory limit

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  #1 (permalink)  
Old 02-19-2008, 05:29 PM
Christer Erlandsson
 
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Default 1 Gb memory limit

Hi, I have 2 Gb of memory in my server but can only use 1 of them today.

Is there a kernel available that can handle larger memories?
Is there any other way to make the system use larger memory?
Do the new kernels have this limit?


/Christer

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  #2 (permalink)  
Old 02-19-2008, 05:30 PM
Damjan
 
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Default Re: 1 Gb memory limit

> Hi, I have 2 Gb of memory in my server but can only use 1 of them today.
>
> Is there a kernel available that can handle larger memories?
> Is there any other way to make the system use larger memory?
> Do the new kernels have this limit?


You will have to recompile the kernel and enable high memory support.

I would suggest you to use a new 2.6 (2.6.9) kernel since it has much
better/more efficient support for that much memory.



--
damjan
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  #3 (permalink)  
Old 02-19-2008, 05:30 PM
Christer Erlandsson
 
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Default Re: 1 Gb memory limit

Thanks for your answer, I'll test that.

/Christer

Damjan wrote:
>>Hi, I have 2 Gb of memory in my server but can only use 1 of them today.
>>
>>Is there a kernel available that can handle larger memories?
>>Is there any other way to make the system use larger memory?
>>Do the new kernels have this limit?

>
>
> You will have to recompile the kernel and enable high memory support.
>
> I would suggest you to use a new 2.6 (2.6.9) kernel since it has much
> better/more efficient support for that much memory.
>
>
>


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  #4 (permalink)  
Old 02-19-2008, 05:30 PM
The Real Slim Shady
 
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Default Re: 1 Gb memory limit

On Thu, 18 Nov 2004 21:00:37 +0000, Christer Erlandsson wrote:

> Hi, I have 2 Gb of memory in my server but can only use 1 of them today.
>
> Is there a kernel available that can handle larger memories? Is there any
> other way to make the system use larger memory? Do the new kernels have
> this limit?
>

Yes, but may I suggest you to switch to AMD64 instead?
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  #5 (permalink)  
Old 02-19-2008, 05:30 PM
Keith Keller
 
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Default Re: 1 Gb memory limit

On 2004-11-18, The Real Slim Shady <Stan@your.house.com> wrote:
> On Thu, 18 Nov 2004 21:00:37 +0000, Christer Erlandsson wrote:
>
>> Hi, I have 2 Gb of memory in my server but can only use 1 of them today.
>>

> Yes, but may I suggest you to switch to AMD64 instead?


I believe a recompile is required for the kernel to be able to address
''large'' amounts of RAM (>1GB) regardless of the CPU used. So I don't
see how your advice is helpful, particularly since the OP already has
his hardware.

--keith

--
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  #6 (permalink)  
Old 02-19-2008, 05:30 PM
The Real Slim Shady
 
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Default Re: 1 Gb memory limit

On Thu, 18 Nov 2004 14:04:15 -0800, Keith Keller wrote:


>>> Hi, I have 2 Gb of memory in my server but can only use 1 of them
>>> today.
>>>

>> Yes, but may I suggest you to switch to AMD64 instead?

>
> I believe a recompile is required for the kernel to be able to address
> ''large'' amounts of RAM (>1GB) regardless of the CPU used. So I don't
> see how your advice is helpful, particularly since the OP already has his
> hardware.

You actually need to recompile for more than 1G ram. However I have no
evidence of kernel's behavior for more than 1G under x86. The fact that
one has to recompile in this case sound highly suspicious about possible
problems.

However since the OP clearly needs a lot of memory, and amd64 is no more
expensive than a 32 bit solution, I would think he would only have
advantages of switching on this platform.
Not to mention it's quite faster in 64 bit mode.

Just my 2 cents.
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  #7 (permalink)  
Old 02-19-2008, 05:30 PM
Chris Newport
 
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Default Re: 1 Gb memory limit

On Thursday 18 November 2004 10:04 pm in alt.os.linux.slackware Keith Keller
wrote:

> On 2004-11-18, The Real Slim Shady <Stan@your.house.com> wrote:
>> On Thu, 18 Nov 2004 21:00:37 +0000, Christer Erlandsson wrote:
>>
>>> Hi, I have 2 Gb of memory in my server but can only use 1 of them today.
>>>

>> Yes, but may I suggest you to switch to AMD64 instead?

>
> I believe a recompile is required for the kernel to be able to address
> ''large'' amounts of RAM (>1GB) regardless of the CPU used. So I don't
> see how your advice is helpful, particularly since the OP already has
> his hardware.


regardless of the CPU used ???
Sparc64 (and most other 64 bit systems) can handle virtually
unlimited memory. The 1Gb limit is an IA86 thing, it does not
apply to other architectures.

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  #8 (permalink)  
Old 02-19-2008, 05:30 PM
Keith Keller
 
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Default Re: 1 Gb memory limit

On 2004-11-19, Chris Newport <me@see-my-sig.invalid> wrote:
>
> regardless of the CPU used ???
> Sparc64 (and most other 64 bit systems) can handle virtually
> unlimited memory. The 1Gb limit is an IA86 thing, it does not
> apply to other architectures.


Yes, but IIRC the kernel option still exists, even if it's not relevant.
So if the OP did decide to take the advice to purchase an AMD64 machine,
and put Slackware on it (which is still 32-bit!), he'd probably want to
recompile the kernel without the <=1GB memory option. (To fully reap
the benefits of the AMD64, of course, he'd need to do a whole lot more
than that.) I do not believe that there is a Slackware 10 pre-built
kernel without the <=1GB option.

At any rate, the OP is probably not benefitting a whole lot from this
tangent.

--keith

--
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  #9 (permalink)  
Old 02-19-2008, 05:30 PM
+Alan Hicks+
 
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Default Re: 1 Gb memory limit

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

In alt.os.linux.slackware, The Real Slim Shady dared to utter,
> You actually need to recompile for more than 1G ram. However I have no
> evidence of kernel's behavior for more than 1G under x86. The fact that
> one has to recompile in this case sound highly suspicious about possible
> problems.


If you have no idea what the hell you're talking about keep your mouth
shut. The linux kernel has options for how much RAM is addressable. The
default config for Slackware kernels doesn't include BIGMEM which
allows 32-bit processors to address up to 4 GB of RAM.

> However since the OP clearly needs a lot of memory, and amd64 is no more
> expensive than a 32 bit solution, I would think he would only have
> advantages of switching on this platform.


AMD64 is more expensive than 32-bit x86 if you've already bought the
32-bit box. GAFC.

> Not to mention it's quite faster in 64 bit mode.


Slackware ain't compiled in 64-bits.

- --
It is better to hear the rebuke of the wise,
Than for a man to hear the song of fools.
Ecclesiastes 7:5
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  #10 (permalink)  
Old 02-19-2008, 05:30 PM
ray
 
Posts: n/a
Default Re: 1 Gb memory limit

On Thu, 18 Nov 2004 21:00:37 +0000, Christer Erlandsson wrote:

> Hi, I have 2 Gb of memory in my server but can only use 1 of them today.
>
> Is there a kernel available that can handle larger memories?
> Is there any other way to make the system use larger memory?
> Do the new kernels have this limit?
>
>
> /Christer


Yes. There is a compile option on the kernel for 4gb or 64gb.

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