[arch-general] Reboot-less Computers
Hi, I am looking at possibilities to have a setup which does not need to be restarted at all and can be live patched. I have seen this old post: http://allanmcrae.com/2015/03/updating-arch-kernel-on-digital-ocean/ And I am reading information about kpatch. But there does not need to be much information. Is there a reliable way to do this currently? If yes, I would like to know some information about it. Ideally, a tried and tested set of steps will be welcome. But things are never so easy I guess. -- Cheers Jayesh Badwaik https://jayeshbadwaik.github.io
On 10/28/18 at 05:43pm, Jayesh Badwaik via arch-general wrote:
Hi,
I am looking at possibilities to have a setup which does not need to be restarted at all and can be live patched. I have seen this old post:
http://allanmcrae.com/2015/03/updating-arch-kernel-on-digital-ocean/
And I am reading information about kpatch. But there does not need to be much information. Is there a reliable way to do this currently? If yes, I would like to know some information about it.
The wiki has an article about kpatch, but note that you will have to maintain your own kernel then. Also kpatch is really geared to updating your kernel for security issues and not updating to a newer version. [1] [1] https://wiki.archlinux.org/index.php/Kernel_live_patching -- Jelle van der Waa
On Sunday, 28 October 2018 21:17:31 CET Jelle van der Waa wrote:
The wiki has an article about kpatch, but note that you will have to maintain your own kernel then. Also kpatch is really geared to updating your kernel for security issues and not updating to a newer version. [1]
[1] https://wiki.archlinux.org/index.php/Kernel_live_patching
Thank you. What are the opinions about kexec? The wiki says " Note that kexec may not work correctly for you due to devices not fully re- initializing when using this method, however this is rarely the case. " https://wiki.archlinux.org/index.php/Kexec -- Jayesh Badwaik https://jayeshbadwaik.github.io
Em outubro 28, 2018 18:23 Jayesh Badwaik via arch-general escreveu:
Thank you. What are the opinions about kexec? The wiki says " Note that kexec may not work correctly for you due to devices not fully re- initializing when using this method, however this is rarely the case. "
kexec should work just fine on recent hardware. I think the last time I used it, I had one issue with nvidia, but having bbswitch fixed it. Keep in mind that kexec is a soft-soft reboot, so, it's not like you're not rebooting the machine. And, in some cases it might be faster and safer to actually reboot the machine. Regards, Giancarlo Razzolini
On Sun, Oct 28, 2018 at 05:43:28PM +0100, Jayesh Badwaik via arch-general
I am looking at possibilities to have a setup which does not need to be restarted at all and can be live patched. I have seen this old post:
I think that if your system is important enough that it shall never go down even for a few minutes, what you really want is additional redundancy in form of a high availability setup. Your hardware and software can fail at any time and then it doesn't matter if you can hotpatch your kernel or not. If you have a HA system, it doesn't matter if you reboot or not because the other node(s) take(s) care of the work for the time being. Also sometimes the power fails and if you don't reboot your machines regularly, they may not come back on after that (ask any bigger data center). If you reboot regularly, chances are higher that you spread out any problems and resolve them before all machines are rebooted at once. If you want to do it for science, all I can say is that I think there are more interesting/important problems than this, but YMMV. Well, and then there's the issue that you need to specifically create the patches and that you can't patch everything because that's just way too much work, but that has already been mentioned by others in this thread. Florian
participants (4)
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Florian Pritz
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Giancarlo Razzolini
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Jayesh Badwaik
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Jelle van der Waa