8GB RAM not showing for Mandrake 10

[cgswong]

Hi all,

I've got a Dell PE6650 (4 CPU, 8GB RAM) that I've installed Mandrake 10. Problem is that Linux only sees 800MB!

What do I need to do to enable the kernel to see and use all 8GB please?

Also, when I choose from the SMP kernel from Lilo boot menu it sees 8 CPU instead of 4? Do I need to choose the SMP kernel boot to get SMP features?

Thanks.

The ONE ( HP-UX + Solaris + AIX + Tru64 = Unix)

 

[skiflyer]

I don't know about the RAM but 4 Intel Pentium 4 processor's will often show as 8 CPU's due to hyper threading exposing multiple cores.

 

[cgswong]

I figured as much on the CPU side though the processors are Xeon and not P4. I thought that Xeons that old didn't have hyperthreading?

Not as important as the memory issue though. I've got the boot option "mem=8096m" as well but it still only shows up as seeing 800 MB.

Any help is very appreciated. Thanks.

The ONE ( HP-UX + Solaris + AIX + Tru64 = Unix)

 

[mattjurado]

Do you really need that much RAM? For memory above 4gb, you need PAE (page address extensions) enabled (and of course, CPUs that support PAE, which I think Xeons do). You do take a slight hit in overall performance, but usually not that noticeable. Also, you'll need applications that specifically are written to take advantage of that extra RAM, which are usually advanced corporate database packages. What's this system for?

Matt J.

Please always take the time to backup any and all data before performing any actions suggested for ANY problem, regardless of how minor a change it might seem. Also test the backup to make sure it is intact.

 

[cgswong]

It's going to house Oracle 10g Application Server, Oracle 10g database (RMAN and EM), and a network management system (NMS). Possibly other software as well if I'm forced to improvise on something.

So if I enable PAE the system will recognize the 8GB RAM? How do I enable the PAE? I did not notice anything in the BIOS or during the Linux installation.

Thanks.

The ONE ( HP-UX + Solaris + AIX + Tru64 = Unix)

 

[mattjurado]

It needs to be compiled in the kernel. I don't use mandrake, so I'm not for certain what tool you need to use, or if you can edit the config file and do it from your command shell. I thought the line was something like

options pae

However, a gui tool may have it right there for you to select.

Speaking of Mandrake, you sure you really want to run that software on Mandrake? I would be looking to run SuSE or Redhat myself. Personally I would use SuSE.

I don't mean to start the old "my fav distribution is better than yours thread" but mandrake was more of a windows user migration distro in my opinion, not a high end database server.


I would have a look at these articles, will probably be informative to you.

http://www.spack.org/index.cgi/LinuxRamLimits

http://www.puschitz.com/TuningLinuxForOracle.shtml

Matt J.

Please always take the time to backup any and all data before performing any actions suggested for ANY problem, regardless of how minor a change it might seem. Also test the backup to make sure it is intact.

 

[sleipnir214]

wongyc2k:

Before you spend a lot of time fighting Mandrake over the RAM issue, I recommend that you read this page from Oracle's website.

They seem to be leaning heavily toward RedHat and SuSE.

Want the best answers? Ask the best questions!

TANSTAAFL!!

 

[cgswong]

Thanks guys. Been very helpful. I recall using the enterprise kernel and seeing 4GB so I rebooted using this and it did indeed pick up 4 out of the 8GB. Would have to compile in the PAE to use it though not sure how to do this as yet.

I looked at both Red Hat and SUSE and decided to go for Red Hat ES 2.1/3. I had a Red Hat 8 system up and running but truth be told didn't like it much. This distro is testing while we get the copy of RH ES in-house though even that may change to SUSE if we can't find a local distributor we like(there's always a local IBM so we could easily get SUSE from them).

Again, thanks.

The ONE ( HP-UX + Solaris + AIX + Tru64 = Unix)

 

[ericbrunson]

8GB is too much ram, you'll do fine with 4GB. You can send me the rest. ;-)

 

[flugh]

And, as a matter of fact, my favorite distro is better than yours ;-)

Go Debian!

(Sorry for the stupid post, it's late and I'm off to bed!)

----
JBR

 

[unixfreak]

Why are you running a system like this on Linux? If you can afford an Oracle licence for this, you can afford a proper Unix system.

Cheers

 

[bfks3230]

Are you using one of those Linux versions that you can buy at Best Buy or CompUSA? It's probably not meant to be used on a monster machine like this one. Get a "server" version and see what happens. You have obviously spent a lot of money--I hope it's worthwhile.

 

[bwilliam13]

You need to be using Redhat AS 2.1/3.

Anything less will NOT support 4 CPU's out of the box unless you recompile your kernel yourself. Even so, you need to have a kernel that supports high memory (up to 64 gig). The only OS that comes with that already working is Red Hat AS 2.1 or 3.

Oracle 10g will not load without a bunch of fenagling and headaches if you are using anything other than Red Hat, Suse, or UnitedLinux. In addition, you'll get support from Oracle using the three afore-mentioned OS'es. You will not get that support with any other versions of Linux...period.

Use this site for reference:

http://www.puschitz.com/

Trust me when I tell you...you need to use methods that Oracle supports. Most, if not all of your problems will cease if you do. I would suggest getting the $1499 version of Red Hat 2.1...the AS version. You'll get unlimited incidents of support for a year. Check it:

http://www.redhat.com/software/rhel/comparison/