[CentOS] After install centos does not find hardrives (SATA)

Thu Feb 16 14:36:18 UTC 2006
Aleksandar Milivojevic <alex at milivojevic.org>

Quoting Nathan <lists at netdigix.com>:

> no its the prompt centos goes to when it cannot find anything to boot to.

So it's the grub prompt most likely.  If it is, then your boot 
partition is either too large and part of it falls outside of BIOS 
addressable disk space (first 1024 cylinders), or is not positioned 
inside BIOS addressable disk space (basically, same thing).  Grub can 
access disk drives only using BIOS calls.  It needs to be able to 
access files in /boot/grub directory, as well as kernel and initrd 
images in /boot directory.  All those files *must* be in BIOS 
addressable range, or booting will fail.  Fdisk will issue a warning 
describing this for disks with more than 1024 cylinders.  
Unfortunately, you won't get such warning during graphical install.  
Grub isn't really verbose about this either (it just drops to CLI, 
without telling user where the problem is).

You can easily check if what I just described is the problem you are 
having.  Boot from CD into rescue mode.  Invoke fdisk and print out 
partition table.  The start and end cylinder of partition that holds 
/boot directory must be bellow 1024.  If they are not, you are in 

If this is the problem you are having, the easiest way is to reinstall 
with above limitations in mind.  Common way of dealing with this BIOS 
limitation is to create separate partition for /boot, and to make sure 
entire partition used for /boot is inside first 1024 cylinders.  For 
example, by making /boot be first partition on the disk, and having it 
relatively small (100MB is more than enough for this partition).  This 
is limitation of the BIOS, nothing to do with CentOS (any other 
operating system).

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