Is a reboot required after RHEL 5 kernel update?

SteveJenkins · 12-07-2009, 11:42 AM

I've found just as many affirmative answers as I have negative while Googling this question. I'd love to know once and for all - is it necessary to reboot the system after updating the kernel on an RHEL 5 box?

We did a yum update and installed a bunch of updates (including a kernel update). Typing "uname -a" displays the following:

Code:

Linux machine.domain.tld 2.6.18-8.1.15.el5 #1 SMP Thu Oct 4 04:06:15 EDT 2007 i686 i686 i386 GNU/Linux

So do we need to reboot or not?

Thanks,

SJ

SteveJenkins · 12-07-2009, 11:47 AM

With some more poking around, I think I answered my own question. I looked in /boot/grub/grub.conf and noticed that the 2.6.18-8 kernel was on the bottom of the list, and that 2.6.18-164 first. So I guess that answers that. A reboot IS required.

Anyone want to talk me out of it before I kill my beloved uptime stat?

lazlow · 12-07-2009, 02:11 PM

No matter what standard distro you are talking about(I seem to recall some specialty distros that were different) you need to reboot in order to install(run) a new kernel. As far as I can remember it is the only package that it is absolutely necessary, although there are a lot of packages it is a whole lot easier to reboot to get to run rather than go through all the hoops to get them to run on a running kernel.

chrism01 · 12-07-2009, 10:50 PM

Going on the prev, you can install on disk(!) a new kernel with no reboot. If you want to run that kernel you must reboot.
As he said, most other sw just requires a restart of the relevant service(s).