Hi there,
I'm currently using CentOS 4.3 (Server edition) in a HP DC 5100 with the IntelR 915GV chipset, powered by a PIV 3.0GHZ.
Now I'm facing a problem, with memory.
I got myself 4GB of memory, the system bios detects it correctly, but in Linux can only see around 3.5gb memory. With the default kernel-smp (I use hyperthread) or with kernel-hugemem , I have the same results.
Is there any way to workaround this issue?
Thanks in advance,
Bruno Sousa
Bruno Sousa wrote:
Hi there,
I'm currently using CentOS 4.3 (Server edition) in a HP DC 5100 with the IntelR 915GV chipset, powered by a PIV 3.0GHZ.
Now I'm facing a problem, with memory.
I got myself 4GB of memory, the system bios detects it correctly, but in Linux can only see around 3.5gb memory. With the default kernel-smp (I use hyperthread) or with kernel-hugemem , I have the same results.
Is there any way to workaround this issue?
It is probably the 4Gb memory hole issue - various 'things' reserve memory below 4GB so hiding the real memory from the OS.
Your BIOS may have a mapping option to map some of this hidden real memory to above 4Gb - however, you need to use a hugemem kernel to access this memory.
James Pearson
Hi there,
It seems like the bios of this machine doesn't have any type of configuration regarding the memory mapping. I'm already using the kernel-hugemem , but the problem remains. What else can be done?
By the way, if the machine had more than one cpu, the problem would remain?
Best regards, Bruno Sousa
-----Mensagem original----- De: centos-bounces@centos.org [mailto:centos-bounces@centos.org] Em nome de James Pearson Enviada: quinta-feira, 22 de Junho de 2006 15:54 Para: CentOS mailing list Assunto: Re: [CentOS] x86 uniprocessor 4GB memory
Bruno Sousa wrote:
Hi there,
I'm currently using CentOS 4.3 (Server edition) in a HP DC 5100 with the IntelR 915GV chipset, powered by a PIV 3.0GHZ.
Now I'm facing a problem, with memory.
I got myself 4GB of memory, the system bios detects it correctly, but in Linux can only see around 3.5gb memory. With the default kernel-smp (I use hyperthread) or with kernel-hugemem , I have the same results.
Is there any way to workaround this issue?
It is probably the 4Gb memory hole issue - various 'things' reserve memory below 4GB so hiding the real memory from the OS.
Your BIOS may have a mapping option to map some of this hidden real memory to above 4Gb - however, you need to use a hugemem kernel to access this memory.
James Pearson _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Hi there,
It seems like the bios of this machine doesn't have any type of configuration regarding the memory mapping. I'm already using the kernel-hugemem , but the problem remains. What else can be done?
By the way, if the machine had more than one cpu, the problem would remain?
Best regards, Bruno Sousa
-----Mensagem original----- De: centos-bounces@centos.org [mailto:centos-bounces@centos.org] Em nome de James Pearson Enviada: quinta-feira, 22 de Junho de 2006 15:54 Para: CentOS mailing list Assunto: Re: [CentOS] x86 uniprocessor 4GB memory
Bruno Sousa wrote:
Hi there,
I'm currently using CentOS 4.3 (Server edition) in a HP DC 5100 with the IntelR 915GV chipset, powered by a PIV 3.0GHZ.
Now I'm facing a problem, with memory.
I got myself 4GB of memory, the system bios detects it correctly, but in Linux can only see around 3.5gb memory. With the default kernel-smp (I use hyperthread) or with kernel-hugemem , I have the same results.
Is there any way to workaround this issue?
It is probably the 4Gb memory hole issue - various 'things' reserve memory below 4GB so hiding the real memory from the OS.
Your BIOS may have a mapping option to map some of this hidden real memory to above 4Gb - however, you need to use a hugemem kernel to access this memory.
Having multiple CPUs would make no difference. The hugemem kernel would only see this memory if the BIOS could map it to above 4Gb - if the BIOS can't, then there is nothing above 4Gb for the hugemem kernel to see.
A newer version of the BIOS _might_ have added this support ...
James Pearson
Hi there, I did the question regarding multiple processors, because it seems like i will be getting na HP ML 350 with 2 Intel Xeon with 4 or 8gb of memory. But will I be able to use 4gb or more?
Thanks, Bruno Sousa
-----Mensagem original----- De: centos-bounces@centos.org [mailto:centos-bounces@centos.org] Em nome de James Pearson Enviada: quinta-feira, 22 de Junho de 2006 17:18 Para: CentOS mailing list Assunto: Re: [CentOS] x86 uniprocessor 4GB memory
Hi there,
It seems like the bios of this machine doesn't have any type of configuration regarding the memory mapping. I'm already using the kernel-hugemem , but the problem remains. What else can be done?
By the way, if the machine had more than one cpu, the problem would
remain?
Best regards, Bruno Sousa
-----Mensagem original----- De: centos-bounces@centos.org [mailto:centos-bounces@centos.org] Em nome
de
James Pearson Enviada: quinta-feira, 22 de Junho de 2006 15:54 Para: CentOS mailing list Assunto: Re: [CentOS] x86 uniprocessor 4GB memory
Bruno Sousa wrote:
Hi there,
I'm currently using CentOS 4.3 (Server edition) in a HP DC 5100 with the IntelR 915GV chipset, powered by a PIV 3.0GHZ.
Now I'm facing a problem, with memory.
I got myself 4GB of memory, the system bios detects it correctly, but in Linux can only see around 3.5gb memory. With the default kernel-smp (I use hyperthread) or with kernel-hugemem , I have the same results.
Is there any way to workaround this issue?
It is probably the 4Gb memory hole issue - various 'things' reserve memory below 4GB so hiding the real memory from the OS.
Your BIOS may have a mapping option to map some of this hidden real memory to above 4Gb - however, you need to use a hugemem kernel to access this memory.
Having multiple CPUs would make no difference. The hugemem kernel would only see this memory if the BIOS could map it to above 4Gb - if the BIOS can't, then there is nothing above 4Gb for the hugemem kernel to see.
A newer version of the BIOS _might_ have added this support ...
James Pearson
_______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
If this is a different mainboard, then it will probably have different characteristics - you probably need to ask your supplier about it ...
James Pearson
Bruno Sousa wrote:
Hi there, I did the question regarding multiple processors, because it seems like i will be getting na HP ML 350 with 2 Intel Xeon with 4 or 8gb of memory. But will I be able to use 4gb or more?
Thanks, Bruno Sousa
-----Mensagem original----- De: centos-bounces@centos.org [mailto:centos-bounces@centos.org] Em nome de James Pearson Enviada: quinta-feira, 22 de Junho de 2006 17:18 Para: CentOS mailing list Assunto: Re: [CentOS] x86 uniprocessor 4GB memory
Hi there,
It seems like the bios of this machine doesn't have any type of configuration regarding the memory mapping. I'm already using the kernel-hugemem , but the problem remains. What else can be done?
By the way, if the machine had more than one cpu, the problem would
remain?
Best regards, Bruno Sousa
-----Mensagem original----- De: centos-bounces@centos.org [mailto:centos-bounces@centos.org] Em nome
de
James Pearson Enviada: quinta-feira, 22 de Junho de 2006 15:54 Para: CentOS mailing list Assunto: Re: [CentOS] x86 uniprocessor 4GB memory
Bruno Sousa wrote:
Hi there,
I'm currently using CentOS 4.3 (Server edition) in a HP DC 5100 with the IntelR 915GV chipset, powered by a PIV 3.0GHZ.
Now I'm facing a problem, with memory.
I got myself 4GB of memory, the system bios detects it correctly, but in Linux can only see around 3.5gb memory. With the default kernel-smp (I use hyperthread) or with kernel-hugemem , I have the same results.
Is there any way to workaround this issue?
It is probably the 4Gb memory hole issue - various 'things' reserve memory below 4GB so hiding the real memory from the OS.
Your BIOS may have a mapping option to map some of this hidden real memory to above 4Gb - however, you need to use a hugemem kernel to access this memory.
Having multiple CPUs would make no difference. The hugemem kernel would only see this memory if the BIOS could map it to above 4Gb - if the BIOS can't, then there is nothing above 4Gb for the hugemem kernel to see.
A newer version of the BIOS _might_ have added this support ...
James Pearson
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
-
Bruno Sousa -
James Pearson