Can I update Kernel without Rebooting?
 

Hello.
Can I update Kernel in any Linux Distro without Rebooting my system?

Thanks.

Every driver would have to be rewritten to work with devices that are already initialized and running. While you switch kernels, every user space process would have to be stopped and restarted anyway, so what would be the point? By that time you may as well reboot.

Yes, you can update your kernel without rebooting. But you need to restart your computer to use the newer kernel. There is no way to use the updated kernel without restarting your system. Until you restart, you will still be using the old kernel you booted into when you started up your computer prior to updating your kernel.

How about :

http://kernelcare.com/

http://blog.agate.io/post/1646051807...hout-rebooting

---------- Post added 07-05-15 at 04:08 AM ----------

How about :

http://kernelcare.com/

http://blog.agate.io/post/1646051807...hout-rebooting

So why did you ask ?.

Thus, Update Kernel need rebooting and I can't use any trick about it.

A basic understanding of search engines should have found this

Kernel 4.0 introduced live kernel patching for security fixes.

Also: https://en.wikipedia.org/wiki/Kexec

Good to know. I heard about this possibly going into the kernel some time ago. I think it was around the time that I was moving across country and then acclimating to a new area. I must have missed that it was added due to being so busy. I wasn't online for about 3 months.

I found some tools like it but they are for Patching :(

Quite honestly, whenever I update the kernel, I want to reboot the machine. I don't want "the most-fundamental software environment under which all other software runs" ... to be changing underneath that software's feet, "on the fly."

Instead, I want "every airplane that is now up in the sky," first, to land (and to turn-off their engines). Then ... and only then ... in the briefly-eerie silence ... I shall "replace The Sky."

A-n-d ... "God forbid" ... if The Sky is suddenly full of smoke and shrapnel :eek: ... I shall have a reliable exit-strategy: I shall quickly repeat the process. When I have done so, I will once again know with certainty "the nature of the air-space that "every(!) Airplane Up There" will encounter.

And, I shall hope, I shall thereby have earned the outcome that every IT-person earnestly hopes for: the prerogative to "go home and eat dinner, perchance to go out to eat," and then to get a good night's sleep, without(!) The Pager Going Off At Some <<deleted>>-UnGodly Hour. :banghead:

:D ...

that looks (at least for me) something like changing your car without sitting into the new one. So yes, you can have several kernels, but only one will be in use at a time. Obviously I can say I have heard there is an os where you can even boot the second kernel without stopping the original one and all the new(?) processes will use the new kernel, but probably that was only a tale.

Two different things have been brought up.

kpatch is a way to apply patches to the running kernel without rebooting. It is experimental. Last I checked RedHat says try at your own risk.

kexec lets you reboot into a new kernel without restarting the BIOS, so it bypasses stuff like memory test. It also doesn't do a hardware reset so all of your devices are in an unknown state and may be active when the new kernel starts. I know of at least one video card that executes a different command set at reset time than after a new kernel boots and runtime firmware is loaded. Does your driver support that?

If you have some time, try to build a small 'LinuxFromScratch' system, and you will find yourself doing just that. Its worth trying at least once.

That process takes you to a totally new system though. I don't believe it would work if you just wanted to update the kernel within the current PATH.