Comment 18 for bug 74179

Again, I'm running the Jaunty RC (2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009 i686 GNU/Linux) on a desktop with 4 GB. The BIOS reports 4GB on startup, but /proc/meminfo says it sees only 2838352 kB (2.75 GB).

I tried the Grub patch suggested in bug 189269 (http://www.howtoforge.com/make-your-xen-pae-kernel-work-with-more-than-4gb-ram-debian-etch-grub). The claim made there was that not all RAM was being seen, and that a small change to Grub (without doing anything to the kernel) fixed the problem.

However, this Grub patch didn't change anything for me -- Ubuntu still saw only 2.75 GB after rebooting with the new Grub in place on my disks.

Since the Grub patch was proposed in the context of the "Xen-PAE kernel", I'm going to guess that the kernel in this case was already PAE-enabled. So perhaps the reason the Grub patch did nothing for me is because I'm running a "desktop" system (and many people have said that the desktop kernel doesn't have PAE enabled). But I just wanted to put it on record that, in my case at least, this Grub patch does *NOT* give me access to any extra memory, and the problem still remains.

Given what others have said about a "server" kernel fixing the problem, I'm not sure what to make of the report that the Xen-PAE kernel wasn't seeing all the memory on the system, and that a patch to Grub was needed as well.

I would still recommend that a PAE-enabled version of the 32-bit desktop kernel ought to be made available for people who have >= 4GB of RAM on their desktops. The two workarounds proposed so far -- using a "server" kernel, or installing a 64-bit system -- seem to have their own problems and don't sound like good general solutions at this time.