LinuxQuestions.org
Welcome to the most active Linux Forum on the web.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 10-14-2007, 03:45 AM   #1
ageo
LQ Newbie
 
Registered: Oct 2007
Posts: 10

Rep: Reputation: 0
Fedora 7 Install Problem!


I'm trying to install Fedora on a Gateway 503GR PC with 3GB of RAM. The installation stops immediately after displaying the message:

agpgart: Detected 7932K stolen memory.

After this I have to power down the computer.

Please let me know how to solve this problem.

Thanks!
 
Old 10-14-2007, 04:07 AM   #2
jay73
LQ Guru
 
Registered: Nov 2006
Location: Belgium
Distribution: Ubuntu 11.04, Debian testing
Posts: 5,019

Rep: Reputation: 130Reputation: 130
Hmm, I wouldn't have expected that to happen with 3GB... Now, with 4GB, one would have to add mem=6144MB and agp=off as boot arguments. Maybe you should try mem=5120MB and agp=off. Just add them as options (you can press one of the F keys).
 
Old 10-14-2007, 10:50 AM   #3
ageo
LQ Newbie
 
Registered: Oct 2007
Posts: 10

Original Poster
Rep: Reputation: 0
Quote:
Originally Posted by jay73 View Post
...try mem=5120MB and agp=off
I can understand agp=off, but why should I specify 5GB of memory (5120MB) when the system only has 3?
 
Old 10-14-2007, 03:10 PM   #4
jay73
LQ Guru
 
Registered: Nov 2006
Location: Belgium
Distribution: Ubuntu 11.04, Debian testing
Posts: 5,019

Rep: Reputation: 130Reputation: 130
With only 3GB you shouldn't have to but apparently you have something special there.

As for the reason, that is rather technical. Many (all?) of today's motherboards assume that you are using a 32 bit system, which means that they have 4GB of memory space. So, at first sight, someone with precisely 4GB of RAM shouldn't have any problems as that amount would seem to fit precisely into the available memory space. Unfortunately, it's a bit more complicated.
The thing is that a computer has to reserve part of its memory space to address devices such as videocards, sound cards, etc. and that this counts just as much as your sticks of RAM. In other words, if the system reserves 1GB for communicating with its devices, there is only 3GB left for your sticks of RAM. As a consequence, you won't be able to see more than 3GB, whether you have a 32 bit operating system or a64 bit one. This should be pretty familiar for anyone trying to put 4GB into a system that runs a 32 bit OS. Help, the system doesn't see all my RAM.

Of course, 64 bit systems are known to accept much larger amounts of RAM so how do they do it given the limited memory space? Well, the BIOS has a trick called memory mapping. With this option enabled, 2GB will be reserved for devices and the other two for RAM; the remaining RAM will be mapped above the 4GB space. A 32 bit system wouldn't be able to access that mapped memory space (without PAE that is) because it doubles the 4GB limitation but a 64 bit one can. Now the situation looks like this to the OS: there is 4GB of memory space + 2 GB of mapped memory = 6GB. While you have only 4GB installed.

So if you have memory mapping enabled and you are using a 64 bit OS, you should tell the system that there is 2 GB more than you actually have. The reason I find your case confusing is that 3GB shouldn't be that problematic. 1GB reserved + 3GB of RAM = 4GB so that should fit properly into the 4GB space. With memory mapping disabled, you should see exactly 3GB regardless of OS architecture; with mapping enabled, you should see 2 if you have a 32 bit OS and all 3 if you have a 64 bit OS. The only reason I can think of to explain issues with 3GB is when a system is assigning more than 1GB to devices. That would happen if one or more devices have excessively large amounts of RAM of their own. For example, some Nvidia 8800s have 768MB of dedicated RAM, which would cause the system to reserve more than 1GB of memory space.

mem=5120MB (or 5GB) is only required when you are using memory mapping; you should be fine without it you aren't.

Last edited by jay73; 10-14-2007 at 03:14 PM.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Fedora install problem tied2 Linux - Software 3 05-31-2007 06:16 PM
Fedora Install Problem Briandr Fedora 5 05-11-2006 07:08 PM
Fedora Install Problem neske Fedora 4 12-05-2005 08:20 AM
Problem install Fedora 4 thierry9584 Fedora - Installation 13 08-20-2005 10:58 PM
fedora install problem Karmek Linux - Newbie 3 03-26-2004 08:45 AM


All times are GMT -5. The time now is 12:40 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration