# Kernel update without reboot?



## elohkcalb (Nov 6, 2013)

Read this the other day, has anyone tried it before on production?

http://korovamilky.tumblr.com/post/16460518079/running-new-linux-kernel-without-rebooting


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## ComputerTrophy (Nov 6, 2013)

Ooooh... this will perform a connection reset. Not ideal. Try this: http://www.ksplice.com/


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## NickM (Nov 6, 2013)

While it's not *technically* a reboot... it's still a reboot, really.


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## scv (Nov 6, 2013)

Hot reboot. Ksplice is what you're looking for.


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## MannDude (Nov 6, 2013)

Ksplice is still a thing? I thought they closed shop years ago.


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## KuJoe (Nov 6, 2013)

You can't buy Ksplice anymore but it does come free when you purchase an Oracle support license. Not sure if anybody is willing to run Oracle's OS on their VPS nodes or pay the price tag associated with it.

Found an old thread on LET about this so I figured I'd include some info from it:

Per Oracle's support:



> Ksplice is a feature of Oracle Linux Premier Support, which is only for systems running Oracle Linux. If you would like to purchase support for other RHEL-based systems you should contact Oracle Linux Support directly (http://www.oracle.com/us/technologies/linux/OracleLinuxSupport/index.html).
> 
> As a side note, Ksplice used to be sold as a stand-alone subscription. While we no longer provide this service we have not dropped support for any distributions for our existing customers.
> 
> Best regards, Tim


At the time I received that reply (July 2012), I ran the following numbers:



> I used the "cost calculator" on the link they provided and a single server with 8 cores and 5 or more virtual guests is $1,199/year. 2 servers would be $2,398/year.


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## NickM (Nov 7, 2013)

Ksplice itself is free software.  If you want to use it with something other than Oracle Linux, you just need the new source and the source of the currently running kernel. A quick google leads to these instructions for doing the whole thing: http://cormander.com/2011/08/how-to-use-the-ksplice-raw-utilities/


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## KuJoe (Nov 7, 2013)

That's reassuring...



> Take this warning very seriously. Whether or not you know what you are doing, expect that you will crash your kernel when you build an update and insert your own ksplice update.


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## NickM (Nov 7, 2013)

KuJoe said:


> That's reassuring...


That is supposedly the warning in the ksplice utilities.  One has to wonder... why would a company that charges for patches to be used with ksplace warn people that making and using your own patches could cause a crash?  And obviously, if you *are* going to patch your live, running kernel, I would hope that you've tested the process extensively on an identical dev machine...


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## KuJoe (Nov 7, 2013)

Keep in mind that the ksplice code that licensed companies are paying for is not the same as the open source code. Even before they stopped selling licenses, the open source code was 2 years behind the stable code that we being pushed.


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## blergh (Nov 7, 2013)

KuJoe said:


> You can't buy Ksplice anymore but it does come free when you purchase an Oracle support license. Not sure if anybody is willing to run Oracle's OS on their VPS nodes or pay the price tag associated with it.
> 
> Found an old thread on LET about this so I figured I'd include some info from it:
> 
> ...


Not entirely true, old users that got it back in the days still have it for the same pricing (grandfathered?) and no need for support-licenses or whatever.

I still have my account with ksplice, it's like 3.5$ per month per server.


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## KuJoe (Nov 7, 2013)

blergh said:


> Not entirely true, old users that got it back in the days still have it for the same pricing (grandfathered?) and no need for support-licenses or whatever.
> 
> I still have my account with ksplice, it's like 3.5$ per month per server.


That is correct. I thought that was already mentioned though.


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## George_Fusioned (Nov 7, 2013)

KuJoe said:


> You can't buy Ksplice anymore


Actually you can still purchase Ksplice licenses through http://www.cpaneldirect.net


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## Awmusic12635 (Nov 8, 2013)

Indeed legacy customers still have full support

Very handy software, we use it on our nodes.


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## Pete M. (Nov 16, 2013)

MannDude said:


> Ksplice is still a thing? I thought they closed shop years ago.


Oracle bought them and are offering a 30 day trial for CentOS/RHEL users. The idea is that after that you switch over to Oracle paid support and Oracle Linux, which is just a RHEL clone (with some extra packages and optianal Oracle modded kernel).


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