Updating the kernel to version 2.6.18-92.1.13.el5 on Red Hat Enterprise Linux 5.1Edit

First we check what updated kernel packages are available:

$ sudo yum --disableexcludes=all check-update 'kernel*'
Password:
Loading "rhnplugin" plugin
rhel-i386-server-5        100% |=========================| 1.4 kB    00:00

kernel.i686                              2.6.18-92.1.13.el5     rhel-i386-server
kernel-headers.i386                      2.6.18-92.1.13.el5     rhel-i386-server

Then perform the actual update:

$ sudo yum --disableexcludes=all update 'kernel*'
Loading "rhnplugin" plugin
rhel-i386-server-5        100% |=========================| 1.4 kB    00:00
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package kernel-headers.i386 0:2.6.18-92.1.13.el5 set to be updated
---> Package kernel.i686 0:2.6.18-92.1.13.el5 set to be installed
--> Finished Dependency Resolution

Dependencies Resolved

=============================================================================
 Package                 Arch       Version          Repository        Size
=============================================================================
Installing:
 kernel                  i686       2.6.18-92.1.13.el5  rhel-i386-server-5   14 M
Updating:
 kernel-headers          i386       2.6.18-92.1.13.el5  rhel-i386-server-5  848 k

Transaction Summary
=============================================================================
Install      1 Package(s)
Update       1 Package(s)
Remove       0 Package(s)

Total download size: 15 M
Is this ok [y/N]: y
Downloading Packages:
(1/2): kernel-2.6.18-92.1 100% |=========================|  14 MB    00:24
(2/2): kernel-headers-2.6 100% |=========================| 848 kB    00:01
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing: kernel                       ######################### [1/3]
  Updating  : kernel-headers               ######################### [2/3]
  Cleanup   : kernel-headers               ######################### [3/3]

Installed: kernel.i686 0:2.6.18-92.1.13.el5
Updated: kernel-headers.i386 0:2.6.18-92.1.13.el5
Complete!

Then cross our fingers and reboot:

$ sudo reboot

Broadcast message from root (pts/0) (Sun Sep 28 12:18:23 2008):

The system is going down for reboot NOW!

As noted in my weblog post, the system took about half an hour to come back online (instead of the expected 60 seconds) because of a forced fsck; the answer to why this kind of check takes place came from INetU support:

Red Hat like many Linux distributions will automatically force a filesystem check if 60 days or more have passed between file system checks it will automatically run at the next to verify drive integrity before mounting them for use.

This was something new to me having come to RHEL 5.1 from RHEL 3, which didn't perform such forced checks. So from here on will have to budget for additional downtime if more than 60 days have passed since the last reboot (or alternatively schedule periodic reboots every 55 days or so).