On Fri, 2006-01-20 at 11:23 -0800, Bruce McPeek wrote:
Hello,
I have a Dell 1850 with dual Xeon procs and two u320 36Gb drives. I would like to set this up as dual boot system with 4.2 on disk 0 and 3.6 on disk 1.
I imagine that I would install 4.2 first and then 3.6. Would I need to remove the other hard drive while installing a given version?
Any gotchas?
Don't run the CentOS-4 fsck on CentOS-3 or vice versa.
How about setting up GRUB? Anything special or does the install take care of it?
I personally would not use a shared /boot partition for both OSes ... as ext3 from CentOS-4 is different than ext3 from CentOS-3 (There are SELinux / ACL extended attributes in CentOS-4 ext3 partitions). I don't even write to CentOS-3 partitions with CentOS-4 ... but that is just me.
You can easily do something like this in Grub (which is what I do on dual boot machines):
Pick one OS as Master ... say, CentOS-4. You would install it first, and during the install, make it write grub to the Master Boot Record (MBR). {This is the default}
After booting to CentOS-4, edit your /boot/grub/grub.conf file and make an entry like this:
title CentOS-3 on Drive2 rootnoverify (hd1,0) chainloader +1
Also find and remove (or remark out with a #) the line that says:
hiddenmenu
Then boot from the CentOS-3 CDs and install CentOS-3 ... keep all the CentOS-3 install on the second drive (well ... you could share the swap file from CentOS-4, but don't share /boot {or any other ext3} partition).
During the CentOS-3 install, select the "Advanced Boot Loader Options" on the Boot Loader Configuration page ... and then for "Install Boot Loader Record on:" pick the 2nd choice {/dev/????? - First Sector of boot partition}
See this install page in the docs for pictures: http://mirror.centos.org/centos/3/docs/html/rhel-ig-x8664-multi-en-3/s1-x86-...
This will allow you to select the "CentOS-3 on Drive2" and boot it ... or to boot the initial CentOS-4 install.