

FreeBSD on EC2 via defenestration - cperciva
http://www.daemonology.net/blog/2011-07-08-FreeBSD-on-EC2-via-defenestration.html

======
thaumaturgy
Yikes. This looks like exactly the kind of patchwork hack (in the "kludge"
sense of the word) that keeps later on biting people in the ass over and over
and over again.

So let's say you have a job for which FreeBSD + EC2 is the right answer (or
you just really like FreeBSD + EC2), so you make use of this, and then it
works for a while and works well so you begin to build some kind of
infrastructure on it, and even though you're paying extra for it, you don't
mind because it works.

The FreeBSD project in the meanwhile gets a little pressure off of their Xen
paravirtualization efforts, which bothers people that would like to use
FreeBSD under Xen not-on-EC2, but maybe that's not a big deal.

Eventually Amazon changes something, since this is exploiting a not-
officially-supported "feature", and the whole mess stops working. People who
were relying on FreeBSD-on-EC2 are hosed, and they're probably not a big
enough market for Amazon to care very much about (although Amazon does have
better support than most companies their size, so maybe they'd do something
about it), FreeBSD still has poor Xen support, and everybody's standing around
with their pants down.

Not very good long-term thinking.

Nice hack though. But I think you'd have to be a little wet-behind-the-ears to
build much on it.

(Much love to FreeBSD, not trolling, etc. etc.)

~~~
lamnk
Agree, why don't people concentrate on the core problem:

    
    
      > FreeBSD's poor paravirtualized Xen support
    

instead of hacking around EC2? (I'm not a programmer)

~~~
cperciva
Two reasons: First, this is a lot of work, and in really scary parts of the
kernel. Second, 99% of places using Xen are now running HVM, so improved PV
Xen support isn't as useful as it sounds.

------
elehack
I like the name of "defenestration" for this technique. Particularly with the
OED reference to back up the technically non-standard but still precedented
usage of the term.

------
mborromeo
This is a great news, thanks for your efforts on this!

However, it's really sad to have to pay the Microsoft toll over FreeBSD (afaik
Windows EC2 Instances are a bit more expensive because the cost of the OS
licence is factored into the hourly cost). I hope Amazon will do something
about this, like providing HVM-based Unix instances.

~~~
cperciva
_I hope Amazon will do something about this, like providing HVM-based Unix
instances._

We can hope. I have a feeling that the larger the number of people running
FreeBSD in EC2, the more likely they are to change this.

------
asharp
This is a random question, but why doesn't amazon just have a HVM flag on
instance creation?

Is it to try and better DRM the windows machines?

~~~
cperciva
_why doesn't amazon just have a HVM flag on instance creation?_

Probably because they didn't need it. Amazon is the most customer-centric
company I know, but this cuts both ways -- I've never seen them add a feature
unless they have customers asking for it.

------
trbecker
Someday people will understand how awesome OpenBSD is, and add it to EC* and
other could services.

~~~
cperciva
I'm happy to help other BSD developers.

------
spartango
Something to keep in mind: HVM is generally slower(even with VT-x) than
paravirtualization...It's not by a huge amount, but you'll definitely be
seeing higher IO latency. While this is a neat hack, you're paying more and
getting poorer performance.

~~~
cperciva
_HVM is generally slower(even with VT-x) than paravirtualization_

Not in this case. The problem you're talking about is with emulated hardware;
EC2 uses paravirtual devices with HVM, so the performance there is identical
to completely paravirtual instances.

------
NatW
Good news, but too bad there aren't small EC2 instances yet.

~~~
cperciva
Working on it. ;-)

