Memory Upgraded, and system boot up becomes very slow

[Alan Cox]

On Tue, 22 May 2007 10:05:41 -0400
shhgs <shhgs.efhilt at gmail.com> wrote:

> Hi all,
> 
> I've just upgraded my system memory from 1GB to 2GB, and I found its
> boot up becomes very very slow.
> 
> Usually the boot up will cost less than one minute, but now it will
> take something like 15 minutes. I found the kernel loading seems quite
> good,  but the problem lies in init loading. It will take minutes  to
> load each service.  I suppose I've choose a wrong kernel, or there
> shold be some special parameters to boot the kernel, but I don't know.
> 
> My mother board is Elite P4M800Pro, and my OS is RHEL 4. If anyone
> knows how to tackle this problem, please let me know.

The usual cause for this is buggy BIOS memory setup. The BIOS has to set
up the cachable memory mappings and if it forgets to do so or misses
chunks then you'll get a very very slow system. Check for BIOS updates.

The other cause can be bad RAM *IF* you are using ECC RAM and getting a
lot of corrected errors and scrubbing going on, but I'd put my first bet
on the BIOS.

If there isn't a new BIOS then you can update the cachable mappings that
are in /proc/mtrr to fix the BIOS screwup and this can be done early in
boot so its annoying but not a disaster.

Alan