why dmesg | grep Memory gives two different physical memory amounts?
 

hello...

I am monitoring physical memory in a server I administer, and my hardware provider told me they had increased physical memory size to 4Gb...

However, using several tools (free -m; top; dmesg | grep Memory; grep MemTotal /proc/meminfo;) I discovered that I actually have 3Gb, not 4...

But, my doubt comes from the fact that dmesg | grem Memory tells me I have
3103396k/4194304k available

The first number is effectively 3Gb, but the second one, is 4! so, why I am looking at this two different numbers? Am I missing something? or is it that my provider is telling me the truth but he hasn't configured things right?

I am not sure if this thread goes in here at this subforum, please correct and redirect me if so...

Thank you very much!

If you have 4 GB or more RAM use the Linux kernel compiled for PAE capable machines. Your machine may not show up total 4GB ram. All you have to do is install PAE kernel package.

This package includes a version of the Linux kernel with support for up to 64GB of high memory. It requires a CPU with Physical Address Extensions (PAE).
The non-PAE kernel can only address up to 4GB of memory. Install the kernel-PAE package if your machine has more than 4GB of memory (>=4GB).

Refer this link to go into more detail:

http://www.dansdata.com/askdan00015.htm