I have been managing a Ubuntu Server 8.04 for quite some time now. On top of it I am running a VMWare Server Edition, which needs to recompile it's modules whenever a new kernel is installed. For that I'm executing:
Until now, whenever a new version of the kernel was available I installed it, rebooted the system and rebuild the modules. But now I realized - rather by accident -, that rebuilding those kernel modules even worked without rebooting the system. VMWare is even able to startup again after that. That made me curious. I entered
uname -r to see the kernel version, which showed me exactly the version I installed right before without rebooting the system.
The Manpages for uname are not exactly detailed on what is actually printed, but so far I thought it printed the actually running kernel version.
My question now is: Is it really possible the kernel reloads itself without rebooting? I did not install ksplice or a similar tool. From what I get it is now even in the repositories for Ubuntu Server 8.04. What's going on with my system? Do I have to reboot after the kernel update or not? What does uname -r print? Is the Ubuntu Server Edition shipped with a program similar to ksplice? I never read anything about a feature like that!
I checked what kees told me to do:
uname -r 2.6.24-28-server
The file in proc gave:
cat /proc/version_signature Ubuntu 2.6.24-28.75-server
dpkg -l 'linux-image*' | grep ^.i ii linux-image-2.6.24-28-server 2.6.24-28.80
Obviously I should do a reboot then :) Thanks for the detailed information!