Announce: OSv, a new open-source operating system for virtual machines

[Nadav Har'El]

On Wed, Sep 18, 2013, Amos Shapira wrote about "Re: Announce: OSv, a new open-source operating system for virtual machines":
> Very interesting.

Hi Amos, thanks. It really is interesting working on this project :-)

> How would this compare to Linux Containers and Docker in terms of memory
> efficiency and performance?

One of the assumptions we made when we decided to write OSv was that the
hypervisor is here to stay. I.e., we already have a whole eco-system of
cloud providers that let you run virtual-machines on top of a hypervisor.
As long as this is true, people will be looking for more efficient
operating systems to run on those virtual machines which they rent
from Amazon or their IT department's private cloud, or whatever.
Containers, while may be a great idea (and personally, I'm a big fan
of that idea), are simply not a solution to the same problem.

The existance of hypervisors is not just a fact-of-life we need to deal
with, they also have the inherent benefit - that different cloud clients can
use different operating systems - each can use a different version of
OSv, or Linux or Windows if they must ;-) With containers, this isn't
exactly the case, and "guests" must all use a very similar OS, on which
they have little control.

About performance, this can be tested, and I don't think the answer is
obvious up-front. It's easy to assume the lighter containers would be
faster and use less memory, but it doesn't necessarily have to be so
when both the hypervisor and the guest OS focus on these issues (like.
OSv does).
Whole pages can be written about this topic, and seeing that you're not
the only one who made this comparison to containers, I'm sure we will
see more discussions about this topic soon. If you're interested in OSv,
I recommend that you join our mailing list (osv-dev at googlegroups.com),
or look once in a while on our site (http://osv.io).

> My team keeps looking for ways to improve the utilisation of our hardware
> for hundreds of Bamboo build agents, so this is the main context I'm asking
> this in. We currently use static KVM agents (Ubuntu 12.04 LTS) and just
> finished a successful spike to look at Docker.

I don't believe anyone tried to run Bamboo on OSv yet (it's only been
public for less than a week :-)) so I can't give you any meaningful
measurement, or even any guarantee that it will work without fixing
bugs or modifying Bamboo (e.g., not to fork()). But we will be happy
if you try, and tell us what you've found out!

Good luck,
Nadav.

> 
> Cheers,
> 
> --Amos
> 
> 
> 
> On 17 September 2013 06:36, Nadav Har'El <nyh at math.technion.ac.il> wrote:
> 
> > Hi, today we've made the first release of OSv, a new operating system for
> > running applications on virtual machines.
> >
> > OSv is free software, released under the BSD license, and you can find it
> > in
> > https://github.com/cloudius-systems/osv and http://www.osv.io.
> > There is also a mailing list: osv-dev at googlegroups.com.
> >
> > These days, most applications running on virtual machines in the cloud run
> > on top of Linux. We all love Linux, but as an all-encompassing operating
> > system for everything from phones to supercomputers, Linux was never
> > really designed for virtual machines; It is big and complex, and it
> > offers features (such as multi-user and multi-process) which are today
> > made redundant by the hypervisor and slow it down. Linux's APIs are many
> > times set in stone by decades of legacy code.
> > All these cost in application performance, and make it harder to innovate.
> >
> > This is why we developed OSv, a new operating system designed to run
> > a single application on a virtual machine. As it runs a single application
> > there is no need for kernel-userspace isolation, reducing context switch
> > costs and unnecessary copying. A design from scratch allowed us to
> > experiment with new ideas like lock-free mutexes (solving the Lock-Holder
> > Preemption problem that plagues operating systems on virtual machines),
> > extremely fast context switches, Van Jacobson's network channels (see
> > http://www.lemis.com/grog/Documentation/vj/lca06vj.pdf), and more.
> > Also, OSv is released under the more permissive BSD license (not GPL
> > like Linux), is tiny compared to Linux, and takes less than one second
> > to boot and start the user's application.
> >
> > OSv can run ordinary Linux shared objects, such as, for example, an
> > unmodified JVM (e.g., OpenJDK) executable, and of course on that you can
> > run any application written in Java, JRuby , Clojure, or any other JVM
> > language. Even at this early stage of OSv's development, OSv can already
> > successfully run several interesting workloads such as Netperf, Memcached,
> > Cassandra and SpecJVM - and usually match or even beat Linux's performance.
> >
> > Another refreshing feature of OSv is that is written in C++.
> > It's been 40 years since Unix was (re)written in C, and the time has
> > come for something better.
> > C++ is not about writing super-complex type hierarchies (as some people
> > might have you believe). Rather, it allowed us to write shorter code
> > with less boiler-plate repetition and less chances for bugs. It allowed
> > us to more easily reuse quality code and data structures. And using
> > newly standardized C++11 features, we were able to write safe concurrent
> > code with standard language features instead of processor-specific
> > hacks. And all of this with zero performance overheads - most of C++'s
> > features, most notably templates, are compile-time features which result
> > in no run-time overhead compared to C code.
> >
> > OSv was developed by Cloudius Systems, a small Israeli startup led by
> > Dor Laor and Avi Kivity (of KVM fame) but it is an open-source project -
> > developed since its inception on github
> > (https://github.com/cloudius-systems/osv), and released under the BSD
> > license. We would like to take this opportunity to invite everyone to use
> > OSv, and to help drive its development forward. OSv is a fantastic
> > playground for kernel developers, and also for people involved in cloud
> > development, devops, and so on. Tell us what your dream VM operating
> > system will do, and maybe your dream will come true :-) Maybe you can even
> > help us make that dream come true.
> >
> > If you want to try OSv, check out the announcement and usage instructions
> > on the OSv mailing list:
> > https://groups.google.com/forum/#!topic/osv-dev/enqdqN2A0as
> >
> >
> > --
> > Nadav Har'El                        |      Monday, Sep 16 2013, 13 Tishri
> > 5774
> > nyh at math.technion.ac.il
> > |-----------------------------------------
> > Phone +972-523-790466, ICQ 13349191 |A computer once beat me at chess,
> > but it
> > http://nadav.harel.org.il           |was no match for me at kickboxing.
> >
> > _______________________________________________
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> >
> 
> 
> 
> -- 
>  [image: View my profile on LinkedIn]
> <http://www.linkedin.com/in/gliderflyer>

-- 
Nadav Har'El                        |      Friday, Sep 20 2013, 16 Tishri 5774
nyh at math.technion.ac.il             |-----------------------------------------
Phone +972-523-790466, ICQ 13349191 |A Life? Cool! Where can I download one of
http://nadav.harel.org.il           |those from?