RHEL5 32bit fresh installation without automatic PAE kernel

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We need to automatically install RHEL 5 (32bit version, kernel 2.6.18-8) on a SUN X4250 with 8 GB RAM.

Does someone know why Kernel Pae is not automatically installed? After the reboot, it is possible to install the pae packages from CDs (and it works!) but we want an unattended installation with a PAE kernel.

In order to install a Pae Kernel (kernel-PAE-2.6.18-8) do I have to insert a special entry on my anaconda file? Is there a BIOS option to set? or anything else? With cat /proc/cpuinfo | grep pae it is possible to understand that the CPUs are pae compatible...

Please, don't suggest to update to 64 bit O.S because we have applications that run only on 32 bit.

Thanks in advance for your suggestions

Alessandro

AA
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rh Red Hat Pro 686 points
20 February 2013 4:35 AM

looks like this feature is added from  anaconda-11.1.2.87-1 onwards ie RHEL5.1.

commit 63ba102cc2e18c6d0bf2b54562c91dcfc4f92236
Author: dcantrel <dcantrel@redhat.com>
Date:   Fri Jul 6 23:16:30 2007 +0000
[..]
    - Install the PAE kernel when applicable (e.g., >4GB memory) <-----------
      Resolves: rhbz#207573
 
 

rh Red Hat Pro 686 points
20 February 2013 4:43 AM

From RHEL5.1 release notes,

"During the installation process, Anaconda can now detect more than 4GB of RAM. This allows Anaconda to automatically determine whether it needs to install the kernel-PAE variant of the kernel or not. "

https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/5/html/5.1_Release_Notes/index.html#sect-Red_Hat_Enterprise_Linux-Release_Notes-Release_Notes_for_x86-Resolved_Issues

Alessandro, you might need to consider installing from RHEL5.1 or higher .

Ranjith Rajaram's picture Red Hat Guru 2215 points
20 February 2013 4:47 AM

If you are using kickstart, In Packages section, you can add line "kernel-PAE" if you want to continue using RHEL 5 GA

%packages
kernel-PAE
AA Active Contributor 150 points
20 February 2013 9:23 AM

Thank you very much. Your suggestion is very precious

AA Active Contributor 150 points
20 February 2013 10:57 AM

Thank you. Now I know that this problem is solved in RHEL5.1, but I want to try your suggestion because I have two doubts.

  1. With my PC (mem=8 GB), adding the "kernel-PAE" line in my kickstart, the kernel-PAE will be the default kernel? if not, I have to modify the /boot/grub/grub.conf!
  2. With another PC (mem=2 GB) and the same previous installation ("kernel-PAE" line in my kickstart), what is the installed kernel?

I will try some tests and I'll write here the results.

Ranjith Rajaram's picture Red Hat Guru 2215 points
20 February 2013 12:11 PM

If you can use 5.1 or higher, then you no longer need to use kernel-PAE in the package section of the kickstart.

If the system has 8GB of RAM, kernel-pae would become the default [I did test this after seeing your question]

If the system only has 2 GB, then in %pre/post section, you can check the same and then modify which kernel you want to use. You will need to do further testing.

If the application is compatible with RHEL 5 update 9, then I would recommend to use the latest
 

AA Active Contributor 150 points
20 February 2013 3:59 PM

Ok, many thanks to all for the support, I have done all the tests; following the final results:

Fresh installation, RHEL5.0, 8GB, default kickstart: /boot/gru/grub.conf is

# grub.conf generated by anaconda
...
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.18-8.el5)
    root (hd0,0)
    kernel /vmlinuz-2.6.18-8.el5 ro root=/dev/VolGroup00/LvRoot
    initrd /initrd-2.6.18-8.el5.img

Fresh installation, RHEL5.8, 8GB, default kickstart: /boot/gru/grub.conf is

# grub.conf generated by anaconda
...
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.18-8.el5PAE)
    root (hd0,0)
    kernel /vmlinuz-2.6.18-8.el5PAE ro root=/dev/VolGroup00/LvRoot
    initrd /initrd-2.6.18-8.el5PAE.img

Fresh installation, RHEL5.0, 2GB, kickstart + kernel-PAE line added

& Fresh installation, RHEL5.0, 8GB, kickstart + kernel-PAE line added: /boot/gru/grub.conf is the same:

# grub.conf generated by anaconda
...
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.18-8.el5PAE)
    root (hd0,0)
    kernel /vmlinuz-2.6.18-8.el5PAE ro root=/dev/VolGroup00/LvRoot
    initrd /initrd-2.6.18-8.el5PAE.img
title Red Hat Enterprise Linux Server-base (2.6.18-8.el5)
    root (hd0,0)
    kernel /vmlinuz-2.6.18-8.el5 ro root=/dev/VolGroup00/LvRoot
    initrd /initrd-2.6.18-8.el5.img
 

Th Guru 2987 points
22 February 2013 9:58 PM

Unfortunately, if using other-than-native RHEL methods to build (e.g., HP Server Automation), that doesn't work. It was one of many headaches I had to endure when supporting an app that used an embedded 32bit Oracle application on a large-memory system. Supporting PAE-enabled systems suuuuuuucks if you can't use a yum repo to do your system updates.