topic Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2 in Operating System - Linux

Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Mon, 16 Jan 2006 11:23:58 GMT

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?

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Oleg Mochkin — Mon, 16 Jan 2006 15:20:30 GMT

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

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Ivan Ferreira — Mon, 16 Jan 2006 15:56:48 GMT

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.

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Tue, 17 Jan 2006 03:22:45 GMT

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.

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Tue, 17 Jan 2006 03:28:53 GMT

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

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Ivan Ferreira — Tue, 17 Jan 2006 06:43:55 GMT

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)

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Tue, 17 Jan 2006 06:54:23 GMT

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.

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Stuart Browne — Tue, 17 Jan 2006 08:14:51 GMT

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

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Tue, 17 Jan 2006 08:23:41 GMT

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

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Ivan Ferreira — Tue, 17 Jan 2006 09:00:56 GMT

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.

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Vipulinux — Tue, 17 Jan 2006 09:54:39 GMT

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

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Tue, 17 Jan 2006 10:18:23 GMT

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

Vipul: Update 6 installed on the box

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

George Liu_4 — Tue, 17 Jan 2006 10:56:23 GMT

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?

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Tue, 17 Jan 2006 13:05:32 GMT

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.

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Steven E. Protter — Tue, 17 Jan 2006 14:47:50 GMT

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

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Wed, 18 Jan 2006 03:59:48 GMT

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.

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Mon, 30 Jan 2006 03:46:10 GMT

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.

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Sophie Nicoud_1 — Thu, 09 Mar 2006 12:13:52 GMT

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 ?

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Carlos M.J. — Fri, 10 Mar 2006 04:18:12 GMT

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.

Re: Redhat Enterprise 3 only detects 3GB on proliant dl145 G2

Sophie Nicoud_1 — Mon, 13 Mar 2006 02:20:49 GMT

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