Hi All,

As i have a typical requirement of installing RH AS4 and RHEL 5 versions to install on the same machine with different instances.

Is it possible to do the same and having the option at the boot time, which one to boot from? if yes, then please mention.

Thanks a ton in advance.
Waiting for positive reply.

Regards
-Kush

Yes. Depending on your particular requirements, you may want to deviate but for flexibility create a slightly larger /boot partition (192M?, 256M?) and then use the rest as a single large PV for VG. Perform the RHEL4 install, name the LV(s) something easily identifying that they belong to RHEL4 install (R4LV00, R4LV01, ...). The swap partition/LV may be shared between them (I see no reason off-hand why not) so you can call it something like swapLV. Only use what you need so that you have ample space available on VG to perform RHEL5 install. Once RHEL4 install is complete, copy grub.conf for your reference and start RHEL5 install, select custom/manual partitioning, assign it the same /boot partition and do NOT format, using the same VG leave the existing ones alone, you may specify to use swapLV for RHEL5 swap, then create your RHEL5 LV(s) (R5LV00, R5LV01, ...) and proceed with installation. once install finishes and booted to RHEL5, make sure that RHEL4 files (kernels and initrds) are still in /boot and check grub.conf. if they are not in grub.conf then add the lines using the reference rhel4 grub.conf from earlier. That should allow you to select which one to boot from grub menu. I say this offers more flexibility by using a "shared" VG between the two instances because it allows allocation of any free space in the VG to either OSes' LV(s) if needed later depending on what is happening.

There are any number of possible ways to configure their dual-boot co-existence on bare-metal hardware. Another option may be to install RHEL5 and use RHEL5/Xen to create virtualized instance(s) of RHEL4 and/or RHEL5. Without knowing the reasons for your requirements/instances, not really sure what may be the best fit for your situation.

Hope this helps.

Hi Rayford,


Thanks for the reply.
Now i am able to see the 2 options for Boot in the Menu at the boot time, but the problem here is , when i try to boot from RHEL 5, it gives an error " File not Found".

I installed RH AS4.6 first and then RHEL 5 without Grub and then copied the grub entry for RHEL 5 into the grub.conf file of RH AS4.6.

Do you have any idea, how to fix this one?

any suggestions will be welcomed.

Thanks n Regards
-Kush