Ksplice Boots the Reboot (Linux Journal) [LWN.net]

Linux Journal looks at Ksplice. "If you happen to be in Berlin or Porto Alegre, Brazil this week, you can learn about the company's offerings first hand — Ksplice President Jeff Arnold and company COO Waseem Daher will present at both LinuxTag 2009 and Fórum Internacional de Software Livre this week. Coinciding with their presentations is the release of a free "demonstration" version of Ksplice Uptrack for consumers using Linux."

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Ksplice Boots the Reboot (Linux Journal)

Posted Jun 26, 2009 20:40 UTC (Fri) by tzafrir (subscriber, #11501) [Link] (8 responses)

So what service do they intend to offer, technically?

A slightly modified kernel?

How compatible will it be to the original kernel provided with the distribution?

What fixes do require a reboot?

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 27, 2009 15:53 UTC (Sat) by mangoo (guest, #32602) [Link]

Essentially, almost all kernel fixes require a reboot.

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 27, 2009 21:00 UTC (Sat) by clugstj (subscriber, #4020) [Link] (6 responses)

RTFN and your questions will be answered.

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 28, 2009 4:30 UTC (Sun) by tzafrir (subscriber, #11501) [Link] (5 responses)

I have. And it has omitted such technical details.

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 28, 2009 12:19 UTC (Sun) by freggy (guest, #37477) [Link] (4 responses)

http://tinyurl.com/lm7kyf

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 28, 2009 14:00 UTC (Sun) by tzafrir (subscriber, #11501) [Link] (1 responses)

And you expect me not to search before asking a question here?

(A. I use Yahoo nad not Google, and B. I disable JS from untrusted sites)

Looking at their FAQ file I'm quite confused:

> Q: Will Ksplice Uptrack work in my companys
> virtualized infrastructure?
>
> A: Yes! Ksplice works perfectly in VMware, Xen,
> Virtuozzo or any other virtualized environment.
> It works on both virtual machine hosts and
> guests, keeping your entire infrastructure secure.

They support Virtuozzo guests? Amazing!

> Q: Do I have to prepare my system specially to
> use Ksplice Uptrack?
>
> A: Not at all. Ksplice is fully compatible with the
> kernels provided by your Linux distribution, and
> with any custom kernels you or your company may
> have made. Even the initial installation process
> is completely rebootless, so Ksplice Uptrack fits
> into your infrastructure with zero disruption.

> Q: Which Ubuntu kernel flavors does Ksplice Uptrack support?
>
> A: Currently, we are only supporting the generic kernel.
> However, we will add support for the server and
> virtual kernels before the end of June.

Slight contradiction? Or just my lousy English?

http://www.ksplice.com/uptrack/faq

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 28, 2009 14:35 UTC (Sun) by freggy (guest, #37477) [Link]

http://en.wikipedia.org/wiki/Ksplice :

Ksplice takes as input only a unified diff and the original kernel source code, and it updates the running kernel correctly, with no further human assistance required

So yes, it works on any kernel, as long as you have the source available. This is not new, and this is not what is being announced here. What is new here is the specific support for Ubuntu. Everything is now integrated in a GUI and users probably don't need to have the sources installed, because everything is pre-compiled for (the specifically supported) Ubuntu kernels.

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 28, 2009 15:26 UTC (Sun) by sbergman27 (guest, #10767) [Link] (1 responses)

http://tinyurl.com/mnqfo8

But I'll give you the answer here, as well. Don't be rude and tell people to just Google stuff. Questions such as tzafrir's can often spark interesting discussion, right here on LWN.net, which goes beyond a simple answer to the question. If you don't care to answer, then don't. Let someone else answer, elaborate, speculate what may be possible in the future, question the value... whatever. Asking why one didn't "Google" adds no value to the conversion. Only noise. Arrogant, elitist noise.

Sorry for the off-topic post. And this will be my one and only post in this thread on the subject. Hopefully, it will contribute to improving the SN ratio overall.

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 29, 2009 13:54 UTC (Mon) by leomilano (guest, #32220) [Link]

I think it does help. I read LWN mostly for the incredibly insightful, informed user posts. And yes, that's the reason I post very little, I am doing my part to let the site keep its high standards, LOL.

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 29, 2009 7:34 UTC (Mon) by mjthayer (guest, #39183) [Link] (1 responses)

It seems to me that this is one area where microkernels have a clear advantage over monolithic ones. Because the system is cleanly split into components, the chance that you can update part of the system at runtime is much higher. (Might not apply to the deepest parts of the system, like the core filesystem code, even if they do run in user space).

Ksplice Boots the Reboot (Linux Journal)

Posted Jun 30, 2009 12:56 UTC (Tue) by alankila (guest, #47141) [Link]

Such update would still require a reboot of that subsystem. A ksplice update can be done live. Their paper speaks of about 0,7 ms downtime for a patch.