Kernel – The kernel is the essential center of a computer operating system, the core that provides basic services for all other parts of the operating system.
Here are 5 ways to identify the running Kernel on your server:
- cat /etc/redhat-release – installed Red Hat Enterprise Linux release
- uname -r – Kernel version currently running
- yum list installed kernel\* -installed kernel versions
- uname -m or uname -arch – processor architecture currently running on
- yum info kernel – view kernel package information
Any Kernel related logs you can find in /var/log/messages and these logs are labeled as the kernel service.
We all know how important it is to keep up with the patching process on our systems.It prevents people from breaking in and doing malicious things, not to mention it keeps the boss from yelling at us, too! To update the kernel package in Red Hat is fairly straightforward.
Using the package manager, you can upgrade the kernel in Red Hat Enterprise Linux server to latest version very easy:
- yum update -y kernel
By using the yum command to update the kernel, you are pulling only the most updated version that Red Hat is making available through the reprepositories. This doesn’t mean that this is the most recent version of the Linux kernel available.If you visit http://www.kernel.org, you can find the most up-to-date kernel available. You should download it in a format you are comfortable using (the site has .tar, .gz,.rpm, and more). If you use common rpm package:
- rpm -ivh kernel-x.x.x-xxx.3.1els.rpm
When updating a kernel with the rpm command, never use the -U option to update.The reason behind this is that the update option erases the prior kernel when updating, whereas the -i option installs the newer kernel alongside the old kernel. If something doesn’t work or goes wrong, you have an older kernel to revert to. You’ve been warned!
Regardless of what method you use, when the update of the kernel is complete, you should verify that boot/grub/grub.conf has been updated to contain a stanza with the updated kernel and that it is set to boot from it. This should happen automatically when updating the kernel via the package manager; however, I recommend that you always verify this for yourself (otherwise, your system may boot incorrectly).