Memory issues on CentOS release 5.7 (Final) x64

Support for the other architectures (X86_64, IA-64, and PowerPC)
sweed29
Posts: 4
Joined: 2011/12/22 08:21:04
Location: Bucharest
Contact:

Memory issues on CentOS release 5.7 (Final) x64

Postby sweed29 » 2011/12/22 08:28:58

Hello there,

I have a HP Small Factor dc7600 computer, running CentOS release 5.7 (Final).


Linux zira.vrem.ro 2.6.18-274.7.1.el5 #1 SMP Thu Oct 20 16:21:01 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux

processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Pentium(R) 4 CPU 3.00GHz
stepping : 10
cpu MHz : 3000.000
cache size : 2048 KB
---
processor : 1
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Pentium(R) 4 CPU 3.00GHz
stepping : 10
cpu MHz : 3000.000
cache size : 2048 KB

The maximum memory accepted by this system is 4 GB RAM. I have installed 4 x 1GB Kingston DDR2 667 MHz modules, updated the bios to the latest version. When I boot, system recognizes all 4GB RAM. But on linux, I have only 3261 MB ram available. Here is what /proc/meminfo shows:


root@zira ~# cat /proc/meminfo
MemTotal: 3340132 kB
MemFree: 1924524 kB
Buffers: 38460 kB
Cached: 562284 kB
SwapCached: 0 kB
Active: 1049964 kB
Inactive: 295424 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 3340132 kB
LowFree: 1924524 kB
SwapTotal: 4096564 kB
SwapFree: 4096564 kB
Dirty: 492 kB
Writeback: 0 kB
AnonPages: 744612 kB
Mapped: 27512 kB
Slab: 29356 kB
PageTables: 19448 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 5766628 kB
Committed_AS: 2770492 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 265824 kB
VmallocChunk: 34359471907 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
Hugepagesize: 2048 kB


grub> displaymem
displaymem
EISA Memory BIOS Interface is present
Address Map BIOS Interface is present
Lower memory: 640K, Upper memory (to first chipset hole): 3072K
[Address Range Descriptor entries immediately follow (values are 64-bit)]
Usable RAM: Base Address: 0x0 X 4GB + 0x0,
Length: 0x0 X 4GB + 0xa0000 bytes
Reserved: Base Address: 0x0 X 4GB + 0xa0000,
Length: 0x0 X 4GB + 0x60000 bytes
Usable RAM: Base Address: 0x0 X 4GB + 0x100000,
Length: 0x0 X 4GB + 0x300000 bytes
grub>

I don't know what to do in order to have my linux box recognize all 4GB ram. Any clues or advices?

Thank you!

DaemonProgrammr
Posts: 78
Joined: 2011/12/12 12:49:46

Re: Memory issues on CentOS release 5.7 (Final) x64

Postby DaemonProgrammr » 2011/12/22 09:18:44

First guess: Memory shared with the videocard?

Not sure if it'd then show up in this list...

sweed29
Posts: 4
Joined: 2011/12/22 08:21:04
Location: Bucharest
Contact:

Re: Memory issues on CentOS release 5.7 (Final) x64

Postby sweed29 » 2011/12/22 11:03:37

Thanks for the reply... I will check that but as far as I know there is nothing related to that in BIOS. The only option related to video card is something like VGA Pallete snopping or so... Not sure what's that but I will try to disable it, maybe it helps...

pschaff
Retired Moderator
Posts: 18276
Joined: 2006/12/13 20:15:34
Location: Tidewater, Virginia, North America
Contact:

Memory issues on CentOS release 5.7 (Final) x64

Postby pschaff » 2011/12/22 12:17:30

Welcome to the CentOS fora. Please see the recommended reading for new users linked in my signature.

Updating would also be advisable. The latest kernel is currently 2.6.18-274.12.1.el5.

If more help is needed then please provide more information about your system by running "./getinfo.sh" and showing us the output file.

sweed29
Posts: 4
Joined: 2011/12/22 08:21:04
Location: Bucharest
Contact:

Re: Memory issues on CentOS release 5.7 (Final) x64

Postby sweed29 » 2011/12/23 08:28:00

Thank you very much for your answers. As requested, I got the getinfo.sh script and executed it on my linux box.

You can see its contents at this address: http://pastebin.centos.org/38190

Any help would be really appreciated!

As far as I know I am running the latest kernel version:
root@zira ~# uname -rvi
2.6.18-274.7.1.el5 #1 SMP Thu Oct 20 16:21:01 EDT 2011 x86_64

If I run yum update, it finds no updates!


Cheers,
Bogdan

pschaff
Retired Moderator
Posts: 18276
Joined: 2006/12/13 20:15:34
Location: Tidewater, Virginia, North America
Contact:

Re: Memory issues on CentOS release 5.7 (Final) x64

Postby pschaff » 2011/12/23 16:41:07

Seem odd you don't have updates as kernel-2.6.18-274.12.1.el5.x86_64.rpm dates back to Nov 30. Your repo configuration does show CentOS [updates] enabled, but it also has a lot of 3rd party repos enabled, several of which are mutually incompatible and some of which (notably Atomic) replace core packages. You have some priorities defined for Atomic and EPEL but the yum priorities plugin is not installed. I suspect you may have rather a mess of replaced packages and dependency issues.

You might show the contents of /etc/yum.repos.d/CentOS-Base.repo - perhaps something is hard-coded to prevent updates.

To see what repos you have installed packages from:

Code: Select all

rpm -qa --qf "%{VENDOR} \n" | sort | uniq

The result should be a list of VENDOR tags. To see the packages from a particular Vendor, for example EPEL:

Code: Select all

rpm -qa --qf "%{NAME} %{VENDOR} \n" | grep "Fedora Project" | cut -d ' ' -f 1 | sort

The result should be a list of EPEL packages.
To show RPMforge packages:

Code: Select all

rpm -qa --qf "%{NAME} %{VENDOR} \n" | grep "Dag Apt" | cut -d ' ' -f 1 | sort


You can repeat for each tag (or unique sub-string) other than "CentOS". If the list includes core packages, you may want to consider replacing them with the official CentOS versions using "yum reinstall ...", "yum downgrade ...", or the very ugly "rpm --oldpackage --force ...", or doing a clean install.

milosb
Posts: 661
Joined: 2009/01/18 00:39:15
Location: 44 49′14″N 20 27′44″E
Contact:

Re: Memory issues on CentOS release 5.7 (Final) x64

Postby milosb » 2011/12/23 22:59:41

The only thing coming to my mind is the case I had after adding 4 GB of RAM to my rather elderly motherboard (Asus P5B-V) - the Memory Remap Feature had to be turned on in BIOS in order for all RAM to be detected. Moreover, at the moment, my system's running with 8GB of RAM just fine.

That's my contribution to this case as far as BIOS is concerned.

jeepster
Posts: 21
Joined: 2010/08/19 02:49:06
Location: WA

Re: Memory issues on CentOS release 5.7 (Final) x64

Postby jeepster » 2011/12/24 06:58:58

It doesn't matter what OS you have. There is a huge range of "reserved addresses" taken out for devices (even if you don't have onboard VGA) that do not map to RAM chips.
3300 MB available out of nominal 4096 MB seems typical.

milosb
Posts: 661
Joined: 2009/01/18 00:39:15
Location: 44 49′14″N 20 27′44″E
Contact:

Re: Memory issues on CentOS release 5.7 (Final) x64

Postby milosb » 2011/12/24 20:49:51

jeepster wrote:
There is a huge range of "reserved addresses" taken out for devices (even if you don't have onboard VGA) that do not map to RAM chips.
3300 MB available out of nominal 4096 MB seems typical.

Yes, but, essentially I must disagree. "Huge range of reserved addresses"? 700MB is too huge IMHO. Besides, it's illogical - for example, why don't these devices "consume" as much RAM when less than 4GB is available?

Moreover, I seem to recall my system reporting amount of RAM in the neighborhood of 3.3GB without the feature I spoke of earlier activated. When everything is set up correctly, I'd expect to see anywhere around 3.9GB available.

sweed29
Posts: 4
Joined: 2011/12/22 08:21:04
Location: Bucharest
Contact:

Re: Memory issues on CentOS release 5.7 (Final) x64

Postby sweed29 » 2011/12/27 08:14:38

Thank you all for responding to my question.

Unfortunatelly I cannot find any BIOS remap option. I updated BIOS to the latest version provided by HP. I tried to remove all the mirrors or repos and try to update kernel but in vain.

The strange thing I guess is the following fact:

Code: Select all

lshw -short
H/W path             Device     Class      Description
======================================================
                                system     HP Compaq dc7600 Small Form Factor (EC837ET#UUW)
/0                              bus        09F8h
/0/1                            memory     128KiB BIOS
/0/5                            processor  Intel(R) Pentium(R) 4 CPU 3.00GHz
/0/5/7                          memory     28KiB L1 cache
/0/5/8                          memory     2MiB L2 cache
/0/6                            processor  CPU [empty]
/0/36                           memory     System Memory
/0/36/0                         memory     1GiB DIMM DDR2 Synchronous 667 MHz (1.5 ns)
/0/36/1                         memory     1GiB DIMM DDR2 Synchronous 667 MHz (1.5 ns)
/0/36/2                         memory     1GiB DIMM DDR2 Synchronous 667 MHz (1.5 ns)
/0/36/3                         memory     1GiB DIMM DDR2 Synchronous 667 MHz (1.5 ns)
/0/37                           memory     Flash Memory
/0/37/0                         memory     1MiB Chip FLASH Non-volatile
/0/0                            memory
/0/2                            memory
/0/100                          bridge     82945G/GZ/P/PL Memory Controller Hub
/0/100/2                        display    82945G/GZ Integrated Graphics Controller
[Moderator edit: Added code tags to preserve formatting.]

So CentOS shows that there are 4 x 1GB chips installed but only use 3261 MB.

I also deactivated soundcard from bios, paralel and serial ports, also searched for any option to remove or disable memory for videocard but such an option does not exist.

In the end, I think I will only use 3261 MB of 4 Gb and that's all because I see no other option.

I am planning to buy a new hard disk also and maybe a clean install of the system could solve this problem.