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Old 09-17-2008, 02:29 PM   #1
brgsousa
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512mb from 4Gb is not recognized on Debian


Hi, I use Debian 4.
I recently installed 1 more Gb of Ram memory (2x512MB) in my machine. The BIOS setup recognizes it, but linux doesn't.
Code:
# uname -a
Linux hostname 2.6.14-2-686-smp #1 SMP Mon Nov 14 14:56:10 UTC 2005 i686 GNU/Linux
# free -m
             total       used       free     shared    buffers     cached
Mem:          3291       1880       1410          0        100       1341
-/+ buffers/cache:        438       2852
Swap:          760          0        760
What can be happening?

Regards
 
Old 09-17-2008, 03:13 PM   #2
jay73
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Yeah, well, 86 bit does not support 4GB of RAM. Check whether you can install the 86 bit kernel-server or move on to 64 bit.
 
Old 09-17-2008, 03:26 PM   #3
Quakeboy02
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Since it's displaying more than 3GB of memory, I don't think it's a kernel config problem, so I doubt switching to a different kernel will change anything. Plus, 32 bit works just fine with up to 4GB. But, as to where the memory went, I dunno, unless there's some set-aside for a graphics card or something like that.
 
Old 09-17-2008, 04:03 PM   #4
neilcpp
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I think your kernel needs to have the right module support for large ram. you need to say what kernel version you are running
 
Old 09-17-2008, 04:05 PM   #5
Quakeboy02
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Quote:
Originally Posted by neilcpp View Post
I think your kernel needs to have the right module support for large ram. you need to say what kernel version you are running
He did. It's in the original post:
Quote:
2.6.14-2-686-smp
 
Old 09-17-2008, 04:15 PM   #6
Quakeboy02
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Quote:
Originally Posted by Quakeboy02 View Post
He did. It's in the original post:
Hmm, having said that, brgsousa, where did you actually get this kernel from? I don't see it on sarge, etch, or lenny.
 
Old 09-18-2008, 07:22 AM   #7
brgsousa
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I got it from aptitude:
Code:
# aptitude show linux-image-2.6.14-2-686-smp
Package: linux-image-2.6.14-2-686-smp
State: installed
Automatically installed: no
Version: 2.6.14-3
Priority: optional
Section: base
Maintainer: Debian Kernel Team <debian-kernel@lists.debian.org>
Uncompressed Size: 51.8M
Depends: yaird | initramfs-tools | linux-initramfs-tool, module-init-tools (>= 0.9.13)
Suggests: linux-doc-2.6.14 | linux-source-2.6.14, lilo (>= 19.1) | grub, fdutils
Conflicts: hotplug (< 0.0.20040105-1)
Provides: linux-image-2.6, linux-image
Description: Linux kernel 2.6.14 image on PPro/Celeron/PII/PIII/P4 SMP machines
 This package provides the binary image and pre-built loadable modules for Linux kernel 2.6.14 on multi-processor Pentium Pro/Celeron/Pentium II/Pentium
 III/Pentium 4 machines.

 This packages is produced using an updated kernel packaging system and replaces older kernel-image packages
Now i am thinking that might not be the right kernel for me:
Code:
# aptitude search linux-image
v   linux-image                                                           -
v   linux-image-2.6                                                       -
v   linux-image-2.6-386                                                   -
p   linux-image-2.6-486                                                   - Linux kernel 2.6 image on x86
p   linux-image-2.6-486-etchnhalf                                         - Linux 2.6-etchnhalf image on x86
p   linux-image-2.6-686                                                   - Linux kernel 2.6 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6-686-bigmem                                            - Linux kernel 2.6 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6-686-bigmem-etchnhalf                                  - Linux 2.6-etchnhalf image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6-686-etchnhalf                                         - Linux 2.6-etchnhalf image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6-686-smp                                               - Linux 2.6 image on PPro/Celeron/PII/PIII/P4 SMP - transition package
p   linux-image-2.6-amd64                                                 - Linux kernel 2.6 image on AMD64
p   linux-image-2.6-amd64-etchnhalf                                       - Linux 2.6-etchnhalf image on AMD64
p   linux-image-2.6-k7                                                    - Linux kernel 2.6 image on AMD K7
p   linux-image-2.6-k7-smp                                                - Linux 2.6 image on AMD K7 SMP - transition package
p   linux-image-2.6-vserver-686                                           - Linux kernel 2.6 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6-vserver-k7                                            - Linux kernel 2.6 image on AMD K7
p   linux-image-2.6-xen-686                                               - Linux kernel 2.6 image on i686
p   linux-image-2.6-xen-vserver-686                                       - Linux kernel 2.6 image on i686
i   linux-image-2.6.14-2-686-smp                                          - Linux kernel 2.6.14 image on PPro/Celeron/PII/PIII/P4 SMP machines
p   linux-image-2.6.18-4-486                                              - Linux 2.6.18 image on x86
p   linux-image-2.6.18-4-686                                              - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-4-686-bigmem                                       - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-4-amd64                                            - Linux 2.6.18 image on AMD64
p   linux-image-2.6.18-4-k7                                               - Linux 2.6.18 image on AMD K7
p   linux-image-2.6.18-4-vserver-686                                      - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-4-vserver-k7                                       - Linux 2.6.18 image on AMD K7
p   linux-image-2.6.18-4-xen-686                                          - Linux 2.6.18 image on i686
p   linux-image-2.6.18-4-xen-vserver-686                                  - Linux 2.6.18 image on i686
p   linux-image-2.6.18-5-486                                              - Linux 2.6.18 image on x86
p   linux-image-2.6.18-5-686                                              - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-5-686-bigmem                                       - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-5-amd64                                            - Linux 2.6.18 image on AMD64
p   linux-image-2.6.18-5-k7                                               - Linux 2.6.18 image on AMD K7
p   linux-image-2.6.18-5-vserver-686                                      - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-5-vserver-k7                                       - Linux 2.6.18 image on AMD K7
p   linux-image-2.6.18-5-xen-686                                          - Linux 2.6.18 image on i686
p   linux-image-2.6.18-5-xen-vserver-686                                  - Linux 2.6.18 image on i686
p   linux-image-2.6.18-6-486                                              - Linux 2.6.18 image on x86
p   linux-image-2.6.18-6-686                                              - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-6-686-bigmem                                       - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-6-amd64                                            - Linux 2.6.18 image on AMD64
p   linux-image-2.6.18-6-k7                                               - Linux 2.6.18 image on AMD K7
p   linux-image-2.6.18-6-vserver-686                                      - Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.18-6-vserver-k7                                       - Linux 2.6.18 image on AMD K7
p   linux-image-2.6.18-6-xen-686                                          - Linux 2.6.18 image on i686
p   linux-image-2.6.18-6-xen-vserver-686                                  - Linux 2.6.18 image on i686
p   linux-image-2.6.24-etchnhalf.1-486                                    - Linux 2.6.24 image on x86
p   linux-image-2.6.24-etchnhalf.1-686                                    - Linux 2.6.24 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.24-etchnhalf.1-686-bigmem                             - Linux 2.6.24 image on PPro/Celeron/PII/PIII/P4
p   linux-image-2.6.24-etchnhalf.1-amd64                                  - Linux 2.6.24 image on AMD64
p   linux-image-486                                                       - Linux kernel image on x86
p   linux-image-686                                                       - Linux kernel image on PPro/Celeron/PII/PIII/P4
p   linux-image-686-bigmem                                                - Linux kernel image on PPro/Celeron/PII/PIII/P4
p   linux-image-amd64                                                     - Linux kernel image on AMD64
p   linux-image-k7                                                        - Linux kernel image on AMD K7
p   linux-image-vserver-686                                               - Linux kernel image on PPro/Celeron/PII/PIII/P4
p   linux-image-vserver-k7                                                - Linux kernel image on AMD K7
p   linux-image-xen-686                                                   - Linux kernel image on i686
p   linux-image-xen-vserver-686                                           - Linux kernel image on i686
 
Old 09-18-2008, 07:35 AM   #8
brgsousa
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I am quite sure if a install linux-image-2.6.18-6-686-bigmem it will be fine
 
Old 09-18-2008, 09:14 AM   #9
johnsfine
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IIRC, a 32-bit kernel can be configured for one of four levels of memory support.

1) Up to 896Mb (I think)
2) Up to 3 and a fraction GB (where the BIOS, not Linux, determines the size of that fraction, typically about 1/4 or 1/2).
3) Up to 16GB
4) Up to 64GB

So it sounds like you have kernel support at the 3 and fraction GB level and want the up to 16GB level. You don't want the up to 64GB level (it has overhead and other issues you don't want).

I'm not sure whether "bigmem" in a prebuilt Debian kernel means up to 16GB or up to 64GB. But I expect it would be up to 16GB. Running a 32-bit kernel on a system with over 16GB would be very strange, doing that and using Debian distribution and wanting to use a prebuilt kernel would be way beyond strange. So it would make no sense for the Debian repository to provide a 32-bit kernel with support for over 16GB.

Last edited by johnsfine; 09-18-2008 at 09:24 AM.
 
Old 09-18-2008, 09:27 AM   #10
i92guboj
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Quote:
Originally Posted by jay73 View Post
Yeah, well, 86 bit does not support 4GB of RAM. Check whether you can install the 86 bit kernel-server or move on to 64 bit.
I guess you mean x86, 32 bits.

You are going to need HIGHMEM enabled if you want to use all your ram under x86 (at a slight penalty), you can as well migrate to 64 bits and use all your ram normally without any problem.

http://kerneltrap.org/node/2450
 
Old 09-18-2008, 06:46 PM   #11
jay73
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Quote:
I guess you mean x86, 32 bits.
Yes, LOL, obviously. I should re-read my messages before I post them.
 
  


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