4:42 p.m.
Hello together,
Why someone shall use KVM, Xen or other hypervisors instead Docker / LXC
Containers on OpenStack?
Thanks!
Arash
4:55 p.m.
On Mon, Feb 17, 2014 at 11:42:21PM +0100, Arash Kaffamanesh wrote:
Why someone shall use KVM, Xen or other hypervisors instead Docker /
LXC
Containers on OpenStack?
Right now, Docker / LXC provide almost no security. When we have SELinux
support, it'll be better, but you're still depending on a shared kernel.
Virtualization provides a much higher level of isolation.
The shared kernel is also limiting in other ways; you are dependent on the
host kernel to have all of the features you need. And of course if you want
a non-Linux system, that's not possible.
Also, I don't think there's currently a good approach for live migration
with containers.
--
Matthew Miller mattdm(a)mattdm.org <http://mattdm.org/>
4:56 p.m.
On Mon, Feb 17, 2014 at 11:42:21PM +0100, Arash Kaffamanesh wrote:
Why someone shall use KVM, Xen or other hypervisors instead Docker /
LXC
Containers on OpenStack?
There are also a number of situations in which a container based
solution may not offer sufficient flexibility. For example:
- A container based solution cannot run a kernel other than the one in
use on the physical host. This may not be compatible with the
operating system your clients want to run.
- A container based solution cannot run a completely different
operating system. People often want to run Windows instances in the
cloud, and occasionally other non-Linux options like FreeBSD.
Additionally, the container driver for OpenStack are not yet as mature
as the hypervisor drivers, and may lack the features or stability to
make them an attractive alternative.
--
Lars Kellogg-Stedman <lars(a)redhat.com> | larsks @ irc
Cloud Engineering / OpenStack | " " @ twitter
5:21 p.m.
Many thanks for your great answers!
So we have to wait for security, stability and live migration support to
become an attractive alternative :-)
Thanks again!
On Mon, Feb 17, 2014 at 11:56 PM, Lars Kellogg-Stedman <lars(a)redhat.com>wrote:
On Mon, Feb 17, 2014 at 11:42:21PM +0100, Arash Kaffamanesh wrote:
> Why someone shall use KVM, Xen or other hypervisors instead Docker / LXC
> Containers on OpenStack?
There are also a number of situations in which a container based
solution may not offer sufficient flexibility. For example:
- A container based solution cannot run a kernel other than the one in
use on the physical host. This may not be compatible with the
operating system your clients want to run.
- A container based solution cannot run a completely different
operating system. People often want to run Windows instances in the
cloud, and occasionally other non-Linux options like FreeBSD.
Additionally, the container driver for OpenStack are not yet as mature
as the hypervisor drivers, and may lack the features or stability to
make them an attractive alternative.
--
Lars Kellogg-Stedman <lars(a)redhat.com> | larsks @ irc
Cloud Engineering / OpenStack | " " @ twitter
6:32 a.m.
On Mon, Feb 17, 2014 at 11:42:21PM +0100, Arash Kaffamanesh wrote:
Hello together,
Why someone shall use KVM, Xen or other hypervisors instead Docker / LXC
Containers on OpenStack?
There's a lot of uninformed, substandard blog-posts talk making the
rounds on the inter-webs.
Rich Jones'(long time open source programmer working on Virtualization)
explains it clearly here:
http://rwmj.wordpress.com/2013/06/19/the-boring-truth-full-virtualization...
--
/kashyap
8:28 a.m.
From Krishnan Subramanian on his blog:
"As we move from a
world of virtual machines to a world of containers, Red
Hat and Docker will emerge as two key players shaping the landscape"
http://allthingsplatforms.com/platforms/the-importance-of-red-hat-docker-...
On Tue, Feb 18, 2014 at 1:32 PM, Kashyap Chamarthy <kchamart(a)redhat.com>wrote:
On Mon, Feb 17, 2014 at 11:42:21PM +0100, Arash Kaffamanesh wrote:
> Hello together,
>
> Why someone shall use KVM, Xen or other hypervisors instead Docker / LXC
> Containers on OpenStack?
There's a lot of uninformed, substandard blog-posts talk making the
rounds on the inter-webs.
Rich Jones'(long time open source programmer working on Virtualization)
explains it clearly here:
http://rwmj.wordpress.com/2013/06/19/the-boring-truth-full-virtualization...
--
/kashyap
9:57 a.m.
On Tue, Feb 18, 2014 at 03:28:20PM +0100, Arash Kaffamanesh wrote:
>From Krishnan Subramanian on his blog:
"As we move from a world of virtual machines to a world of containers, Red
Hat and Docker will emerge as two key players shaping the landscape"
Honestly, don't read too much into any single blog post.
--
/kashyap
2:11 a.m.
On 02/18/2014 04:57 PM, Kashyap Chamarthy wrote:
On Tue, Feb 18, 2014 at 03:28:20PM +0100, Arash Kaffamanesh wrote:
> >From Krishnan Subramanian on his blog:
> "As we move from a world of virtual machines to a world of containers, Red
> Hat and Docker will emerge as two key players shaping the landscape"
Honestly, don't read too much into any single blog post.
Totally agree... Experiences with Solaris Containers PROOVES, that
Container Technology has very specific use cases, and typically fails
due to OPERATIONAL incapabilities of the organisations...
So, Docker as well as containers will not be the solution to all things
"virtualization" as well as "management"...
Still, Docker is an important part, but it will definitively NOT replace
hypervisors (Type 1!). With Type 1 hypervisors standard operations can
still be applied (on top of RHEV or VMware!), and that's the simply
reason, why they've been so successful!
Matthias
--
Red Hat GmbH
Matthias Pfützner
Solution Architect, Cloud
MesseTurm
60308 Frankfurt/Main
phone: +49 69 365051 031
mobile: +49 172 7724032
fax: +49 69 365051 001
email: matthias.pfuetzner(a)redhat.com
___________________________________________________________________________
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Handelsregister: Amtsgericht München, HRB 153243
Geschäftsführer: Charles Cachera, Michael Cunningham, Paul Hickey, Charles Peters
11:24 a.m.
On 18.02.2014 16:57, Kashyap Chamarthy wrote:
On Tue, Feb 18, 2014 at 03:28:20PM +0100, Arash Kaffamanesh wrote:
> >From Krishnan Subramanian on his blog:
> "As we move from a world of virtual machines to a world of containers, Red
> Hat and Docker will emerge as two key players shaping the landscape"
Honestly, don't read too much into any single blog post.
> http://allthingsplatforms.com/platforms/the-importance-of-red-hat-docker-...
To be honest when I finally started playing with Docker I was a bit
underwhelmed. It seems to be not much more than basic tooling around the
linux namespacing capabilities.
The libvirt-sandbox/systemd-nspawn stuff seems to be a much better fit
for this kind of thing as it is geared more at isolating processes in a
usable way whereas Docker appears to aim at running a full System as a
container which is really what the kvm/xen/whatever approach is better for.
What the CoreOS guys are doing with systemd is also interesting:
https://coreos.com/blog/cluster-level-container-orchestration/
Regards,
Dennis
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8 comments
6 participants
participants (6)
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Arash Kaffamanesh -
Dennis Jacobfeuerborn -
Kashyap Chamarthy -
Lars Kellogg-Stedman -
Matthew Miller -
Matthias Pfützner