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20feetputt
16th May 2008, 11:34 PM
I tried to increase the memory from 2 Gb to 6 GB on my Fedora 7, kernel 2.6.23.15-80 x86_64 system.
As a result, during bootup, starting udev fails and the machine hangs.
I thought that 6 GB would be supported on a x86_64 system?
Do I need to tweak something?

TIA

Firewing1
17th May 2008, 12:38 AM
Are there any specific error messages from udev? As well, try removing the sticks one by one and see if there's one RAM stick in particular that's causing the problem.
Firewing1

stevea
17th May 2008, 01:00 AM
Uhhh - I can't recall the detail, but isn't there a BIOS switch to set ?

20feetputt
17th May 2008, 08:33 AM
I have tried all combinations of memory modules with the same result. Anything more than 3 GB fails.
The BIOS recognizes all memory when I insert the additional 4GB.
This is a dual boot machine and with 6GB of memory installed, it boots fine with Vista (32 bits, so only 3 GB is recognized).
When I install the extra memory and udev hangs, I find no trace of any messages in the messages file...

brebs
17th May 2008, 09:10 AM
Stick memtest on a bootable CD (http://www.memtest.org/#downiso), and run it.

RAM can be unstable, especially since we're penny-pinching with non-error-checking (http://www.tech-faq.com/ecc-memory.shtml) RAM.

gvmichel
17th May 2008, 05:06 PM
I'm running 4GB (2x2) on FC9 64bit. Running fine.

My only issue is that it is very slow... probably due to the video driver.

Muhahahahaz
18th May 2008, 06:42 AM
Well I can tell you that there are no special BIOS settings or anything. I would suspect that something may be wrong with the RAM. I'm running 8GB of RAM in F9, and I didn't do anything special.

majikthise
18th May 2008, 09:38 AM
6Gig sounds like a wierd figure to have installed. Is it running in dual-channel mode?

1. Did you check the mobo manual to see which dimm slot configurations are acceptable?
2. Are all sticks of memory the same brand and timings. (buffered, unbuffered or registered - again check mobo manual)
3. Can you boot any other Linuxes ?

You might want to increase the size of your Swap partition to match the new mem-size.

brebs
18th May 2008, 11:12 AM
6gb is fine. Same as my PC. It's just 2 sticks of 2gb, and 2 sticks of 1gb.

majikthise
18th May 2008, 11:28 AM
I try to put sticks of equal size in these days, as I've encountered past problems with half of a stick's capacity not being seen by the system. But hey, that's going back to SDRAM, maybe those sorts of quirks don't crop up nowadays.

20feetputt
18th May 2008, 04:47 PM
I've done some further experimenting and could boot the system without problem with 3GB of memory installed.
Going to 4Gb results in a udev: "wait timeout, continuing in background" message after a very long time. (That's why I thought the machine was hanging.) Boot then continues, but very, very slowly.
Looking in dmesg, I can then see that the kernel has recognized the 4GB, but the system is unusable because of the very sluggish behaviour.
I have also enabled udev loging but can't make anything of it.

DelSol
21st May 2008, 02:26 PM
ok, i also had that issue once. some people called it the 4gb intel bug, where fedora was very, very, very slow and couldn't boot normal no more. sounds like your issue. reducing ram to 3gb solved that issue. other linuxes don't have that problem only opensolaris doesn't boot with 4gb and certain intel boards.

fedora 9 is not affected by that bug, letting you install, boot and work without any ram issues.

20feetputt
21st May 2008, 07:52 PM
Interesting.
I do have an Intel mobo...
I will try to upgrade to F9. Can't do this right away though.

DelSol
21st May 2008, 09:36 PM
that's what i figured, since i never heard about a similar bug on non intel boards. try an bios update, if that doesn't help you need to go on to f9 oder try a different linux like ubuntu whitch is not affected by that bug.

andgeo
26th May 2008, 05:48 PM
I tried to increase the memory from 2 Gb to 6 GB on my Fedora 7, kernel 2.6.23.15-80 x86_64 system.
As a result, during bootup, starting udev fails and the machine hangs.
I thought that 6 GB would be supported on a x86_64 system?
Do I need to tweak something?

TIA
I bet your mobo is an ASUS .The only way to see amount of memory more than 3,2GB is to have the BIOS Option "Memory remap Feature " Enabled . Otherwise the system sees 3.2GB no matter how much memory you have installed . I have the same issue with 2 different MObos of ASUS P5E and Maximus Formula . I can only boot with memory map Feature disabled . I also have an ABIT mb which boots without problems . I havent find any solution yet . BIOS ver is the latest at both the mobos .

DelSol
26th May 2008, 09:08 PM
open your eyes, he allready said its an intel.

andgeo
26th May 2008, 11:52 PM
open your eyes, he allready said its an intel.
ppl used to say Intel while they mean intel based chipset motherboard .Its not clear ... And dont being rude

andgeo
27th May 2008, 09:59 AM
do the trick ... change the default runlevel to 3(*) ... With my mb is the only way to have all the memory which is installed to my system . Login as user and with "su" change the runlevel to 5 with the command "init 5" .
*vi /etc/inittab
and change the 5 at "id:5:initdefault:" with 3