Re: [vserver] Linux 3.13.1 Patch for Testing ...

From: Adrian Reyer <are_at_lihas.de>
Date: Sat 01 Feb 2014 - 10:44:36 GMT
Message-ID: <20140201104436.GA16795@r2d2.s.lihas.de>

Hi,

On Sat, Feb 01, 2014 at 09:26:23AM +0000, Gordan Bobic wrote:
> Can some of the LXC components in the kernel be used in place of the
> relevant VServer components to make the patch smaller and easier to
> maintain? Or if the VServer component is "better" (I use the term
> loosely because what kernel maintainers deem "better" isn't
> necessarily what other people deem "better"), trying to push a patch
> to do that upstream?

I have not checked the code, but I have the impression Herbert uses new
features that arrive in the kernel and enhance or replace features he
implemented himself earlier. E.g. memory limits now done with cgroups.
I have the impression Herbert is not intrested in the hassle involved in
trying to get some code included into mainline kernels.
I personally regard the vserver an ever decreasing patch in terms of
size as more features arrive within the kernel. If it evolves like I
hope, one day we will have all features in mainline accompanied by
util-vserver, which I like much, much better than any lxc-tools I have
seen so far.

> I'm not sure about the general use case, but the impression I get
> from listening on the list is that most people tend to use LTS
> kernels because that is what the distro kernels tend to be based on.
> Would it perhaps be more reasonable to focus on maintaining the
> patch only for LTS kernels? They are still moving targets, but at
> least they would be fewer moving targets.

We mostly use the 3.4 and 3.10 kernels we provide ourselves and for many
szenarios a longterm supported kernel is just the right thing. However,
there are szenarios where you need more recent kernels and would like to
have VServer support nonetheless. Obvious one are new hardware only
supported by recent kernels and missing backports. A new feature would
e.g. live migration of a VServer to some other host by using criu
(http://criu.org/). I have not looked deeply into this one, minimum
kernel is 3.11. But it seems to me criu could enable me to actually
live-migrate VServers I run on top of DRBD-Clusters. If I get it right,
criu actually came from OpenVZ and the most recent LXC uses criu for
exactly the same purpose.
To my understanding, VServer can do everything mainline can plus the
added features. Same time not limited to a specific cpu architecture. If
mainline supports freezing tasks, VSevrer will. If mainline starts and
cook dinner, VServer will be able to do so as well.

> Thank you for VServer. I still firmly believe that it is the "best"
> of the 3 available chroot virtualization solutions for Linux,
> especially due to it's hashify feature.

Same here.

Regards,
        Adrian

-- 
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Received on Sat Feb 1 10:44:47 2014
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