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Old 04-26-2008, 05:27 PM   #1
Micro420
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Why does Ubuntu 8.04 only see 3.5GB instead of 4GB? Yes, PAE is enabled


When I was using CentOS 5.1 x86, it had no problems seeing all 4GB of memory. With the new Ubuntu 8.04 x86, it only shows 3.5GB free. I loaded the /boot/config-`uname` in menuconfig and the default configuration shows that 4GB memory support is enabled, along with PAE. So what gives? Why only 3.5GB?
 
Old 04-26-2008, 07:31 PM   #2
jay73
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This is probably not what you want to hear but with 4GB of RAM it would make sense to install the 64 bit version. It really doesn't make much of a difference anymore. I'm sure that you know what you are doing, it just seems a bit counterintuitive.

And yes, it does look as if PAE is enabled as 3.5GB is already more than the default kernel will support. Did you try the linux-server kernel?
 
Old 04-26-2008, 10:05 PM   #3
Smedley
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I have recompiled my kernel for 64GB of RAM and I can see all 4GB now.
 
Old 04-27-2008, 12:49 AM   #4
Micro420
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Originally Posted by Smedley View Post
I have recompiled my kernel for 64GB of RAM and I can see all 4GB now.
Thanks! I will recompile my kernel with the 64GB option. I just found it odd since the original Ubuntu config file already shows 4GB memory support with PAE. On my old CentOS 5.1 32-bit system, I also had it on 4GB memory support with PAE and it saw all 4GB.
 
Old 04-28-2008, 01:27 AM   #5
Micro420
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I gave up on Ubuntu 8.04 because I could not compile the kernel. I got all these errors, and I am not familiar with compiling a Debian/Ubuntu based distro.

So, I decided to try Fedora 8 and I had the same problem with Fedora 8 only seeing 3.5GB instead of all 4! I am going back to CentOS 5.1. It was fun while it lasted, I think ...
 
Old 04-28-2008, 01:31 AM   #6
Smedley
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Originally Posted by Micro420 View Post
I gave up on Ubuntu 8.04 because I could not compile the kernel. I got all these errors, and I am not familiar with compiling a Debian/Ubuntu based distro.

So, I decided to try Fedora 8 and I had the same problem with Fedora 8 only seeing 3.5GB instead of all 4! I am going back to CentOS 5.1. It was fun while it lasted, I think ...
Bummer, that's what I like Slackware, you can do anything with it.
 
Old 04-28-2008, 11:00 AM   #7
Micro420
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Bummer, that's what I like Slackware, you can do anything with it.
Never tried Slackware. I couldn't even download Slackware. When you go to Slackware.com, there is no download section. Very odd!

As for being able to do it all, I'm sure there was a way to compile a kernel in Ubuntu since I did read many "how-to's" online. I kept getting some kind of asm.c error when issuing the 'make' command. Never experienced problems compiling kernels in CentOS. CentOS is so straight forward: make, make modules, make modules_install, make install. Done! None of this apt-get huh wtf lib1337 followed by a dpkg -i -v -a -z -l -1 -b -c --comment=-blah --huh /root rm -rf kernel-2.9.999 stuff followed by a sudo fakeroot kernel-2.9.999 --comment=more options /aaaaa

Last edited by Micro420; 04-28-2008 at 11:01 AM.
 
Old 04-28-2008, 03:43 PM   #8
Smedley
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Never tried Slackware. I couldn't even download Slackware. When you go to Slackware.com, there is no download section. Very odd!
Here it is, the section is called Get Slack:

http://slackware.com/getslack/

Pick a mirror close to you........Happy Slacking
 
Old 06-06-2008, 10:16 PM   #9
JReinis
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Quote:
Originally Posted by Smedley View Post
I have recompiled my kernel for 64GB of RAM and I can see all 4GB now.
How did you make it?
Any step-by-steps?
Is there Ubuntu 8.04 LTS Desktop?
Thx.

Last edited by JReinis; 06-06-2008 at 10:21 PM.
 
  


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