Debian Problems after RAM upgrade
 

Hello,

I have a Dell Dimension 521 with 2 x 512 MB ddr2 - ram. Recently I bought another 3 x 1GB slices and plugged them into my PC, replacing one of the 512 MB rams ( my motherboard has four slots). Within Windows XP (32 bit) everything seems to be ok. When starting my Debian Etch (amd64) the kernel boots and gdm is loaded well. But when I log in to the Gnome env, the pc hangs. The same happends when logging into fvwm, with the only difference that the pc does not hang immediatly after loggin in but after a random time span. THus the system is highly unstable and in fact unusable under debian. I use the 2.6.23 kernel (compiled by myself - worked fine till the upgrade). Due to the things I have read I think I should mention that I got an ATI Radeon X1300 and the fglrx driver. Also, I read something about an option for grub that should be included ( This has been implied by another thread, I dont know wether this option is for 32 bit systems to handle more than 4 GB or whatever...)

thank you!

michael

the reason is your swap file partition now is to small to handle the ram. at 512 your install created a i gig swap file. so get a free coppy of puppy linux run it live start use gparted to resize yor partions. windows dosnt care it just steals more space on the vurtual ram drive but that dosent mean it uses the upgrade corecctly. that is the problem you need about twice the space of your ram. the swap file partition takes the ram unlodes it on to the partition. so if your ram is larger then your swap linux will crash. windows dose'nt care it steals more space a ruins any files in the way lol.

I suggest running lshw -C memory to see what the system says about memory. All the DELL PC's I have tell me what the maximum amount of RAM the system supports. you may have exceeded that system spec.

The system may want RAM installed in matching pairs and you stated you had 512 MB in one slot and 1 GB in it's mated slot.

In this example you can plainly see the system will accept a maximum of 2 GB per the response.

So you are saying that you got 1x512 mb and 3x1gb sticks in there?

Same speed and all that good stuff??

If the speed of the ram is different your BIOS might get things setup the wrong way - it needs to be at the spped of the slowest ram in there or things will get real buggy.Voltages and timings also might be touchy.

Mixing ram of different sizes,speed and manufacturers is in general considered something you might get lucky with but nobody can guarantee it.

Pull the remaining 512 stick and see what that does - also you might need the big memory (or so) option enabled in the kernel that allows for more than 4 GB ram.

@Drakeo - I don't really follow there.I am running Debian with 2 gig ram w/o swap whatsoever - nothing,nada.

if you dont have a swap partition then linux will get very unstable but if in linux you type cfdisk /dev/hda1 or if you have a sata drive type cfdisk /dev/sda1 it wiil show your partition linux will not run with out a swap partition. unless you load a live cd into ram. if you know for sure you dont have a swap partition let me know / go to you /etc/fstab file open it and it will say in there if you start linux with out a swap file it will stop loading and tell you cant find swap.

Drakeo

While I am a big fan of swapfiles (4gb on a machine with 2gb ram) for systems that have exceeded the base ram requirement (usually 512) they will not prevent the system from starting. Once you start running stuff it may complain but I know of a lot of people who do not run a swap at all with just 1gb of ram without any issues.

Vidar

Try puting in just two of the 1gb sticks and running memtest86 for at least an hour. If that passes, swap out one of the 1gb sticks for the third stick and retest. If all three pass the test you know the memory is good (a lot of new sticks are bad from the start). Next I would move the two known good sticks into the open slots and retest. If you have never used the other slots they may have been bad from the factory. Even if they were good at one point they may also have become damaged since. If all this has passed it may be that your motherboard cannot take mixing sizes. So try two 512s and two 1gb.

The OP seems gone but just for reference I want to mention that I saw a discussion (think it was on kerneltrap) where there where issues mentioned starting at about 3,5 gig ram if you don't have highmem enabled in the kernel.
The Debian kernel (as probably any other distro kernel) has this enabled by default but since the OP did his own - dunno.

Thank you for your help!

Finally I found out that the problem was caused by the fglrx driver, well, at least: Since I switched back to the vesa - driver I do not experience any problems anymore. I do not really know why ( I mentioned before that I read something about that driver and possible memory mapping problems or something similar to this - but this is nothing I am familiar with) - Perhaps someone in here knows why smething like this happens. Its rather a workaround than a real fix, but at least I am able to WORK again:)
Thanks again for your efforts