Multiple kernel in one RHEL 5 Linux
 

Hi

I am new to Linux, and have seen on few linux servers and workstations that they have more then just one kernel.
During boot, they state few kernels, and they boot just one (configured in grub.conf)

The question is, is there some HOW TO guide on how to set multiple kernels in single machine, but without using internet connection and RHN.

There workstations are off the internet (closed network), and I am interested into setting another kernel beside already existing.

Existing is 2.6.18-164.el5, and I want the same one, but PAE, since I want more then 4G on her (it's a VM, so adding memory is an easy task)

thank you

Well there is nothing interesting about this. Just install the appropriate RPM and it'll sort it out for you.

hmm, not so
 

I've taken rpm from rhel's ftp site and placed it in /tmp/kernel folder:

#ls -l /tmp/kernel
total 273212
-rw-r--r-- 1 root root 75420211 Aug 17 08:35 kernel-2.6.18-164.el5.src.rpm
-rw-r--r-- 1 root root 29979401 Aug 17 08:35 kernel-debuginfo-common-2.6.18-164.el5.i686.rpm
-rw-r--r-- 1 root root 174065358 Aug 17 08:36 kernel-PAE-debuginfo-2.6.18-164.el5.i686.rpm
drwxr-xr-x 2 root root 4096 Aug 17 08:39 repodata
#createrepo /tmp/kernel
#yum udate kernel
#reboot

and it shows :

#uname -r
2.6.18-164.el5

I've tried finding some vmlinuz files on file sistem, but all it dound was on /boot, and that is
vmlinuz-2.6.18-164.el5

So, I am doing someting wrong....

I've tried even
# rpm -ivh kernel-debuginfo-common-2.6.18-164.el5.i686.rpm
# rpm -ivh kernel-PAE-debuginfo-2.6.18-164.el5.i686.rpm
#reboot

but that did not do the trick either.

hmmm.....

you've shown any output of those yum commands so I've not a clue what they did, nor how your system is configured. Just installed the RPM directly with the rpm command and that will install it. you'll need to choose the right kernel on boot from the grub menu or change it in /boot/grub/grub.conf if it is not set as the default.

herre it is
 

reverted snapshot, and did it again

here is some output:

# ls -l /tmp/kernel/
total 199476
-rw-r--r-- 1 root root 29979401 Aug 17 12:24 kernel-debuginfo-common-2.6.18-164.el5.i686.rpm
-rw-r--r-- 1 root root 174065358 Aug 17 12:24 kernel-PAE-debuginfo-2.6.18-164.el5.i686.rpm

# createrepo /tmp/kernel
2/2 - kernel-debuginfo-common-2.6.18-164.el5.i686.rpm
Saving Primary metadata
Saving file lists metadata
Saving other metadata

# ls -l /tmp/kernel/
total 199480
-rw-r--r-- 1 root root 29979401 Aug 17 12:24 kernel-debuginfo-common-2.6.18-164.el5.i686.rpm
-rw-r--r-- 1 root root 174065358 Aug 17 12:24 kernel-PAE-debuginfo-2.6.18-164.el5.i686.rpm
drwxr-xr-x 2 root root 4096 Aug 17 12:25 repodata


with system-config-packages, created kernel repo

# cat kernel.repo
[kernel]
enabled = 1
name = kernel
baseurl = file:///tmp/kernel

# yum update kernel
Loaded plugins: rhnplugin, security
This system is not registered with RHN.
RHN support will be disabled.
kernel | 951 B 00:00
kernel/primary | 1.0 kB 00:00
kernel 2/2
Skipping security plugin, no data
Setting up Update Process
No Packages marked for Update

# yum install kernel
Loaded plugins: rhnplugin, security
This system is not registered with RHN.
RHN support will be disabled.
Setting up Install Process
Package kernel-2.6.18-164.el5.i686 already installed and latest version
Nothing to do

#rpm -ivh /tmp/kernel/kernel-debuginfo-common-2.6.18-164.el5.i686.rpm
warning: kernel-debuginfo-common-2.6.18-164.el5.i686.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing... ########################################### [100%]
1:kernel-debuginfo-common########################################### [100%]

rpm -ivh kernel-PAE-debuginfo-2.6.18-164.el5.i686.rpm
warning: kernel-PAE-debuginfo-2.6.18-164.el5.i686.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing... ########################################### [100%]
1:kernel-PAE-debuginfo ########################################### [100%]

Reboot, and nothing
:)

Am I installing what I should, or am I doing the rong way?

Just to add, there is no vmlinuz other then the one started, and nothing new in grub.conf

debuginfo is debug information, not a kernel. uninstall that and install the proper kernel rpm. There is no need to revert snapshots and the likes, this is pretty trivial stuff.

The PAE rpm is on the installation media. just get it off of the DVD.

that is it.

I did not know where to look

thank you