My Linux only sees 3.6GB memory but I have 6

TheStupid · 09-18-2007, 05:41 PM

Why my Linux only sees 3.6GB memory while I have 6GB installed? It's CentOS 5.0 and I installed 4GB more after I installed the OS. This is an IBM x360 machine with 4 Xeon CPUs

any idea?

GrapefruiTgirl · 09-18-2007, 05:53 PM

I'd suggest first considering whether 'high-memory' support is enabled in the kernel you are running.
By default, the average kernel is configured for less than 4 GB, so you may end up recompiling your kernel and enabling support for > 4GB

TheStupid · 09-18-2007, 05:54 PM

The high memory is set at 4GB.

I read some more and it seems I need to upgrade my kernel to kernel-PAE?

How do I do that?

docalton · 09-18-2007, 05:58 PM

You will use a command like

yum install kernel-PAE

I think that is the name of the package you'll need. You can find the package by using a command like

yum search kernel (This will return lots, but what you are looking for will be in there)

Hope this helps

TheStupid · 09-18-2007, 09:39 PM

then what?

Quote:

Originally Posted by docalton

You will use a command like

yum install kernel-PAE

I think that is the name of the package you'll need. You can find the package by using a command like

yum search kernel (This will return lots, but what you are looking for will be in there)

Hope this helps

TheStupid · 09-19-2007, 09:21 AM

Upgraded to kernel-PAE and kernel-PAE-devel, then changed GRUB to load PAE kernel, and then it works.

docalton · 09-19-2007, 11:54 AM

Nice job, I would have thought that yum should have added the grub entries, it did when I did that.

Sorry for leaving out that step.

Glad you got it working.

TheStupid · 09-19-2007, 05:09 PM

It did add the GRUB entry, but by default, it still loads the non-PAE. So i had to modify it to load PAE on default.