Ubuntu
ksplice package

How does ksplice work with Update Manager?

Asked by Aaron Whitehouse

How does KSplice interact with Update Manager?

I have read the KSplice site about how it all works, but I have two remaining questions:
(1) Does KSplice *only* modify the running version of the kernel? Does Update Manager continue to download the new versions of the kernel and write them to the HDD, but the running one is patched by KSplice, or does KSplice do both (I would prefer it to only touch the running one so that, worst case, I could reboot to a standard Ubuntu kernel)?
(2) What happens with notifications? At the moment, if I install updates with Update Manager, I occasionally get a prompt telling me that I need to reboot. If I had Ksplice running, would this go away?
(3) Related to (2), if both Update Manager and KSplice be set to automatically update for security updates, will I never get prompted to reboot again and always be protected (I assume that I would still have to restart X for some updates)?

I currently use Mythbuntu as a PVR and don't update (restart) frequently because something is often recording. This would seem a great solution for me, especially as there is no charge for Uptrack for Ubuntu desktop.

Question information

Language:
English Edit question
Status:
Solved
For:
Ubuntu ksplice Edit question
Assignee:
No assignee Edit question
Solved by:
Evan Broder
Solved:
Last query:
Last reply:
Revision history for this message
Best Evan Broder (broder) said : 		#1

You've mostly got the right idea about how this works.

Ksplice Uptrack only updates the kernel as it's running in memory, not the kernel that's installed on your hard drive. You would use Update Manager to update the latter. If you choose not to update the kernel on your hard drive using Update Manager, then when you reboot Ksplice Uptrack will immediately bring your system up to date with the latest patches.

Within Debian and Ubuntu, packages use a common system to indicate that the system needs to be rebooted to finish applying the updates. However, because Ksplice Uptrack updates the kernel without requiring a reboot, it intercepts and suppresses reboot notifications that would otherwise come from kernel packages. So if you have Ksplice Uptrack installed and you upgrade your linux-image-whatever package, you won't get a reboot notification.

As for your last question, the vast majority of package updates that trigger a reboot are kernel updates, and Ksplice Uptrack can prevent you from needing a reboot for all kernel updates. However, there are on rare occasions updates to non-kernel components that have been so deeply integrated into the system that those updates can not be fully applied without a reboot. D-Bus is an example of this. Ksplice Uptrack doesn't apply patches to non-kernel components such as D-Bus. If you wished to remain protected from all security issues and an update to one of these core packages occurs, you would need to reboot. However, these sorts of updates happen very rarely, if at all.

Revision history for this message
Aaron Whitehouse (aaron-whitehouse) said : 		#2

Thanks Evan Broder, that solved my question.

Revision history for this message
Aaron Whitehouse (aaron-whitehouse) said : 		#3

(That was an excellent answer, thanks Evan!)