Fedora 10, 4GB, PAE

So after recently installing Fedora 10 on a half decent machine and running VMWare Server 2.0, I discovered I didn’t really have enough memory in the host machine. A measly 2GB was blitzed by a couple of Windows Server 2003 guest machines with one as a Domain Controller with 256MB allocated and the other running Exchange Server 2003 SP2 and Microsoft Antigen 9 with 1GB allocated.

I decided to replace the 2GB with four sticks of 1GB CRUCIAL DDR2 PC26400 but, having experienced the memory issue with Windows XP only seeing 2GB RAM, I wasn’t massively surprised with what I saw in Fedora when I ran:

Yes, the 2GB limit applies here too! 🙁

But all was not lost. I decided to investigate to see if there was a solution, knowing about several bits and pieces with memory limitations on Windows Servers I knew it was worth investigating.

Some digging turned up that if I installed kernel-PAE in Fedora and ensured memory mapping was enabled in my BIOS, I should get the full 4GB! Huzzah! I busily set about installing kernel-PAE and rebooted…

When rebooting I headed in to the BIOS and noticed that of course, memory mapping was already enabled (hence the 2GB limit, otherwise it would be 3GB + change) so I allowed the reboot to complete and… there’s still 2GB in there! 🙁

Yet MORE digging turned up that I was booting with the wrong kernel and not the PAE enabled kernel I had just installed so a quick edit of grub.conf following the wonderful advice in this forum entry finally enabled me to see and utilise the full 4GB in Fedora 10.

Now to see if I can add that damned PAE switch to Windows XP SP3 and get the full benefit of the 4GB installed in that too!