[CentOS-virt] Package updates and "required" reboots

Fri May 6 14:45:16 UTC 2011
Stephen Harris <lists at spuddy.org>

On Fri, May 06, 2011 at 09:45:31AM -0400, Ben M. wrote:
> With CentOS Xen 5.6 (standard installation, SELinux enabled) is there an FAQ or 
> general user consensus as to when to do a reboot after what updates?

In my opinion, is the change sufficiently urgent that existing running
processes need to pick it up?

For example, a glibc patch means the new glibc will be executed by new
processes, but already running programs will have the old glibc mapped
into memory; if there's a security issue with the old glibc then already
running processes may still be exploitable.

Another example could be the tzdata patches; if your timezone is
impacted then existing processes may not pick up the changes unless
they're restarted.

Of course a new kernel doesn't run until you reboot :-)

I tend to reboot after glibc and kernel patches, but not normally after
any other (but I do restart services as necessary, eg httpd after an
apache patch).