[SOLVED] memory less reported

[rjnlinux]

My Linux server is having the following issue

We have two servers

Server A
=========
The server was having 2 sticks of 1 GB Ram = tot 2 GB
we have added 2 more sticks of 2 GB each = tot 6 GB

Funny thing - but After install when we started the machine it did detect the total 6 GB Ram so it seems that the BIOS was able to recognize the 6 GB.


I ran the following commands
cat /etc/SuSE-release


SUSE LINUX Enterprise Server 9 (i586)
VERSION = 9
PATCHLEVEL = 3



cat /proc/meminfo|grep Mem

MemTotal: 3630956 kB
MemFree: 2204956 kB


I expect to see total 6 GB

On Second server
================
We did the same on another server
here we increased from 6GB to 10 GB and the server was able to detect the 10 GB

cat /etc/SuSE-release
SUSE LINUX Enterprise Server 9 (i586)
VERSION = 9
PATCHLEVEL = 3


cat /proc/meminfo|grep Mem

MemTotal: 10324860 kB
MemFree: 1502784 kB



The issue is being faced on the first server

Both servers are the same hardware and have 6 slots each capable of handling 2 GB RAM


Please assist

[oz]

You need 64-bit Linux to make use of 4GB of RAM or more.

[rjnlinux]

ozar- two servers
one says 10 GB approx
other says 3.6 GB approx

I am confused

[HROAdmin26]

Google: pae physical address extension

If they're both 32 bit kernels, one machine may support PAE while the other does not.

Server A
=========
The server was having 2 sticks of 1 GB Ram = tot 2 GB

On Second server
================
We did the same on another server
here we increased from 6GB to 10 GB and the server was able to detect the 10 GB

So when you installed the OS on Server A, because only 2GB of memory was installed, the non-PAE kernel was installed. On Server B, the PAE kernel was installed. If you added memory to Server A *and* the hardware supports PAE, you would still not see the additional RAM unless the PAE kernel is installed. Review your kernel versions.

[rjnlinux]

how do i find if PAE is supported ?

[oz]

ozar- two servers
one says 10 GB approx
other says 3.6 GB approx

I am confused

Don't know, but I'd guess the one reporting 10GB is wrong unless PAE has been enabled in the kernel:

Physical Address Extension - Wikipedia, the free encyclopedia

Here's more on the 32-bit vs 64-bit RAM issue:

Clearing up the 32/64-bit memory limit confusion


Edit: oops, looks like you guys were already discussing PAE while I was putting my post together.

[rjnlinux]

10 gb server has the following kernel

uname -r
2.6.5-7.244-bigsmp

server having issue has

uname -r
2.6.5-7.244-smp


so this is the issue - huh ?

so what is the solution ?

[oz]

so what is the solution ?

Maybe you can install the bigsmp kernel or enable it on the other server:

http://www.novell.com/coolsolutions/tip/16262.html

[rjnlinux]

Thanks for the link

this explains the problem but not the solution

How do I switch from smp kernel to bigsmp kernel ?

[oz]

Check to see if you can install the bigsmp kernel using Yast.

I think that if you check the bigsmp kernel and uncheck the smp kernel, Yast should take care of it. You could leave the smp kernel installed until you know the bigsmp kernel is working properly if you'd feel safer doing so.