Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

[Carlos M.J.]

We are setting up a brand new proliant DL185 G2, we have installed 8GB (4*512MB, 2*1024MB and 2*2048MB) and installed RedHat Enterprise Linux v3, but we only get 3GB of memory on /proc/meminfo.

Here it is the output of meminfo:

# cat /proc/meminfo
total: used: free: shared: buffers: cached:
Mem: 3144138752 137883648 3006255104 0 14295040 51867648
Swap: 1073733632 0 1073733632
MemTotal: 3070448 kB
MemFree: 2935796 kB
MemShared: 0 kB
Buffers: 13960 kB
Cached: 50652 kB
SwapCached: 0 kB
Active: 78408 kB
ActiveAnon: 31328 kB
ActiveCache: 47080 kB
Inact_dirty: 12952 kB
Inact_laundry: 4192 kB
Inact_clean: 0 kB
Inact_target: 19108 kB
HighTotal: 2227328 kB
HighFree: 2139604 kB
LowTotal: 843120 kB
LowFree: 796192 kB
SwapTotal: 1048568 kB
SwapFree: 1048568 kB
CommitLimit: 2583792 kB
Committed_AS: 41520 kB
HugePages_Total: 0
HugePages_Free: 0
Hugepagesize: 4096 kB

Could somebody help me to find where are the other 5GB?

[Oleg Mochkin]

read about linux large memory support at http://kerneltrap.org/node/2450 , BR, Oleg

[Ivan Ferreira]

What is the kernel that you are using?

Try installing the kernel-hugemem package:

rpm -ivh kernel-hugemem

Select that kernel to boot, do not use rpm -Uvh to install the kernel.

[Carlos M.J.]

RHEL v3 is certified to support up to 16GB of RAM memory, and up to 2 physical processors.

http://www.in.redhat.com/software/rhel/faq/#2

We have a Proliant DL385 with 4GB of RAM and RHEL v3, and we have no problem with memory. Besides we have tested this DL145 with 4GB and we get only 3GB of memory too.

[Carlos M.J.]

Ooops, in both cases the kernel is:
2.4.21-37.ELsmp

[Ivan Ferreira]

The fact is that:

kernel
- Uniprocessor support for x86 and Athlon systems
- For x86 systems, only the first 4 GB of RAM is used; use the kernel-hugemem package for x86 systems with over 4 GB of RAM


kernel-hugemem
- Support for more than 4 GB of RAM (up to 64 GB for x86)
- PAE (Physical Address Extension) or 3 level paging on x86 processors that support PAE
- Support for multiple processors

kernel-smp
- Multi-processor support
- Support for more than 4 GB of RAM (up to 16 GB for x86)

[Carlos M.J.]

As far as I know RHEL v3 with SMP kernel supports this ammount of memory up to 16GB.

As I said, another server with same version of kernel can handle 4GB of memory without problem.

[Stuart Browne]

Dumb question time. When the machine boots up, it sees all 8GB in the BIOS checks?

[Carlos M.J.]

No dumb question, i didn't mention it.
Yes BIOS shows 8GB on both DL145G2 but RHEL3 reports only 3GB.

[Ivan Ferreira]

I think that in proliant system, you need to setup the operating system type in the BIOS. Have you do that?

Also, try booting the kernel with the mem parameter:

On grub, press "a"

type:

mem=8G

Enter.

[Vipulinux]

Have you tried the latest update CD for RHAS 3.0 (update 5)

[Carlos M.J.]

Ivan: Kernel forced with 8G didn't work (nice try)

Vipul: Update 6 installed on the box

[George Liu_4]

I guess it is a HP BIOS related. Could you post the "BIOS-provided physical RAM map" and
"user-defined physical RAM map" from dmeg?

[Carlos M.J.]

This is the memory map on DL145G2
8GB of memory, memory is paired in Banks.

Dimm1: 512MB
Dimm2: 512MB
Dimm3: 1024MB
Dimm4: 1024MB
Dimm5: 512MB
Dimm6: 512MB
Dimm7: 2048MB
Dimm8: 2048MB

Dimm 1,2,3 and 4 belong to processor 1
Dimm 5,6,7 and 8 belong to processor 2

On dmesg you can see this:
Memory: 3065472k/4194304k available (1662k kernel code, 74720k reserved, 1274k data, 228k init, 2227328k highmem)

there is a "cat /proc/meminfo" at the beginning of the document for more information.

[Steven E. Protter]

Shalom,

The only way to see all 8 GB is to use the bigmem kernel.

Another thing, many servers will not recognize memory unless it is arranged from largest to smallest. Shut down the server and put all the Big chips together at one end of the row of slots and all the small ones together.

The slots really don't belong to particular processors, so there will be no imbalance.

SEP

[Carlos M.J.]

Hi Steven:

More memory configurations was tested. One of this was putting the big chips together. But in all cases the result was 3GB (except in the case there was only 1GB on the machine, of course ;-)

Redhat Enterprise SMP kernels support large amounts of memory up to 16GB, as Ivan said.

[Carlos M.J.]

Hi, there is a specific Redhat version for AMD64 with a specific kernel compiled for AMD64, and it works fine with memory.

The 32 bits version does not recognize all the memory on DL145G2 so please install this version instead.

Thanks everybody for your help.

[Sophie Nicoud_1]

I have same problem with DL145 G2.
4GB of memory are installed, only 3GB are recognized by RHEL3 kernel-hugemem. (I must use a 32Bit version of RHEL3 I can't use a 64bit version of kernel due of software used.)
I have DL145 previous generation (G1) and all 4GB of memory are recognized by Redhat.

What is the matter with DL145 G2 ?

[Carlos M.J.]

Hi:

RedHat Support pointed to install kernel-hugemem but it didn't work. The first attempt was:

up2date -f kernel-hugemem

But you will have to point to an old valid kernel entry on grub to start it up. It was not possible to start from this one, I suppose it was a problem with initial ramdisk (initrd), it cannot find some modules.

The second attempt was to download this file by itself and install with:

rpm -ivh kernel-hugemem

But we didn't do it because we used specific AMD kernel and everything was ok.

If you can spend time testing, I recommend you to generate kernel by yourself modifying /usr/src/linux-2.4/makefile and using a /usr/src/linux-2.4/.config copied from /usr/src/linux-2.4/configs, dont forget to generate initial ramdisk with mkinitrd, and modify grub to allow boot from this kernel. I did not test it, so you will waste your time.

Keep in mind you will loose redhat support doing this, so this is only for testing purposes.

[Sophie Nicoud_1]

Hi,

The same Redhat release works on DL145 G1 (previous version of DL145) and on Sun machines, all machines have 4GB of RAM and 2 opteron processors, this done 16 other hosts running !.
Only 16 new ones (DL145 G2) don't recognize all its memory !!!!

Bye

[bandeira]

Have any of you found the solution to this problem? I've the same question on a DL145 G2. Only sees 3Gb out of 4Gb.

[Carlos M.J.]

Yes, the solution to this thread is to install RedHat Linux for X86_64.

I cannot see more than 3MB with i386 releases.

Hope this helps you.

[Mike Johnson_14]

Carlos, I actually just put in a case with Redhat on this issue because their documentation clearly states that RHEL3 32bit supports up to 16GB of RAM.

The answer almost certainly is that setup chose to install the athlon kernel which does not support PAE, thus won't see memory over 4GB.

Notice from the 2 commands below that a regular rpm query will not show that you have the athlon kernel loaded, but the 3rd command will.

rpm -qa | grep kernel
kernel-smp-2.4.21-37.EL
...continues.

rpm -qi kernel-smp-2.4.21-37.EL output doesn't have the word athlon in the output anywhere.

However, this is the command Redhat had me run:
rpm -q -a --queryformat='%{N}-%{V}-%{R}.%{arch}\n'|grep kernel

It returned 2 kernels in the list of output and they are:
kernel-smp-2.4.21-37.EL.athlon
kernel-2.4.21-37.EL.athlon

So, the official answer from Redhat is to install kernel-smp-2.4.21-37.0.1.EL.i686.rpm.

The kbase article is at http://kbase.redhat.com/faq/FAQ_43_3551.shtm

From this and other documentation, it appears that you have to run the smp kernel even if you have a single processor, which according to more documentation, will not cause any problems.