

Virtual Machines Vs. Containers: A Matter Of Scope - wslh
http://www.networkcomputing.com/cloud-infrastructure/virtual-machines-vs-containers-a-matter-of-scope/a/d-id/1269190

======
mpweiher
We _should_ need neither VMs nor Containers. The process isolation and
environment virtualization provided by the OS should be sufficient, that's
what it is there for.

The fact that it is not seems like a huge failure both in terms of application
architecture that assumes it owns an entire machine and operating system
technology that can't prevent this.

VMs always seemed like a ridiculous (expensive, over-engineered, under-
performing, mis-applied, ...) solution to that problem (they're fine for
OS/hardware simulation etc.), but containers look like a nice, minimal
extension to the isolation offered by the OS.

~~~
travem
> We should need neither VMs nor Containers. The process isolation and
> environment virtualization provided by the OS should be sufficient, that's
> what it is there for.

This is of course assuming that there is a common OS that supports the
applications that people actually want to deploy. Virtualization at the x86
level has taken off partly because of the support for mixed operating systems.
This has provided operations teams additional flexibility and enabled some
consolidation of disparate workloads on shared hardware.

~~~
mpweiher
>This is of course assuming that there is a common OS that supports the
applications that people actually want to deploy.

I think you missed:

"(they're fine for OS/hardware simulation etc.)"

~~~
travem
Thanks for pointing that out, I didn't catch the precise scope of the problem
you were calling out in my initial reading.

------
twic
_Asking this question led me to ask other questions. In particular, is
abandoning full-machine virtualization for containers a real possibility? Is
this a move that cloud architects should truly be considering?_

It's a move FreeBSD, Solaris, and mainframe users made years ago (although it
was full-machine, er, physicalisation they abandoned), since when i imagine
they've been sitting around staring at the Linux industry's VM frenzy with
bafflement.

------
wernerb
I'm surprised I haven't seen anything being said about reproducability
advantages of docker.

Docker images are always reproducable through their Dockerfile's. While
virtual 'appliances/images/snapshots' are - if at all - much harder to
reproduce.

~~~
wmf
It's pretty easy to write a Dockerfile that isn't completely reproducible,
like anything that uses apt-get.

I would also say that VM images should be built in an automated way, although
VMs do allow you to shoot yourself in the foot.

