[CentOS] How to change Disk sequence on DELL R900 CENTOS 5.3?

Thu Jul 2 22:53:15 UTC 2009
Jay Leafey <jay.leafey at mindless.com>

If you are not hung up on the device name changing, i.e. the device must 
ALWAYS be /dev/sda1 or /dev/hda1, you can use LABEL=? or UUID=? in 
/etc/fstab, or use LVM to create logical volumes that do not depend on 
the actual device name.

By default, a fresh install will label the filesystem for /boot as 
"/boot" and put the following line in /etc/fstab:

> LABEL=/boot             /boot                   ext3    defaults        1 2

This works just fine, but if you would prefer something that does not 
depend on labels you can determine the UUID of the device using vol_id 
and put that in /etc/fstab.  For example, on my system the boot device 
happens to be /dev/sda3 for the moment.  I can determine the UUID of 
that device file as follows:

> [root at b82526 ~]# /lib/udev/vol_id /dev/sda3
> ID_FS_USAGE=filesystem
> ID_FS_TYPE=ext3
> ID_FS_UUID=93ffbfba-d42b-48fb-aaf3-90e563b12dc0
> ID_FS_LABEL=/boot
> [root at b82526 ~]#

Using that information, I can use the ID_FS_LABEL value in fstab using 
LABEL=, like the installer does, or I can use the ID_FS_UUID value in a 
UUID= line.  For example:

> UUID=93ffbfba-d42b-48fb-aaf3-90e563b12dc0             /boot                   ext3    defaults        1 2

If it's not the /boot filesystem you are dealing with you can also use 
LVM.  I believe there are several good references on using LVM 
available, including the Red hat-provided docs, that explain the 
procedures better than I can.

Hope that gives you a starting-point!
Jay Leafey - Memphis, TN
jay.leafey at mindless.com