Multiple Linux OS are available for booting…

[Rui Vilao]

Hi all,

Still a beginners question…

I have successfully installed my RHEL 3.0 system…

When I boot two OS are available (the first one is selected by default):

Red Hat Enterprise Linux AS (2.4.21-37.ELsmp)
Red Hat Enterprise Linux AS-up (2.4.21-37.EL)


My question is:

Why are there two OS? Which one shall I use by default?

Any help/suggestion is highly appreciated.

TIA.

Kind Regards,

Rui Vilao.

[Steven E. Protter · Accepted solution]

Shalom Rui,

The one you use by default is in this file: /boot/grub/grub.conf

The default line says which one from the top, starting with zero you will boot from.

You really don't have two OS's.

You have two kernels of the same OS.

This is a pretty common outcome when you install on one of Intel's new hyperthreading CPU's which has two logical cpu's built into one physical CPU.

SMP boot will gain you substantially quicker performance.

SEP

[Vipulinux]

Hi Rui

It seems that you are using a SMP Server, when you install linux on a dual (multi) cpu machine, it will install a SMP kernel along with the normal kernel.

You should use the smp kernel as it is customised for a dual(multi) cpu machine.

Cheers
Vipul

[Muthukumar_5]

Based on your processor available in your machine. View /proc/cpuinfo file and if you have multiple processor then you can use smp kernel.

SMP - http://www.faqs.org/docs/Linux-HOWTO/SMP-HOWTO.html

--
Muthu