[sf-lug] license count != software popularity (Re: [Balug-Talk] Open Source less popular than Free Software)

[Asheesh Laroia]

On Wed, 26 Sep 2007, jim stockford wrote:

> On Sep 26, 2007, at 8:48 AM, Asheesh Laroia wrote:
>
>> You know, I have been going on about how great virtualization is lately.
>> (-;
>
>   I forget. what do you like about virtualization? for whom is
> its various benefits great?

For me! (-:

>    i've seen small outfits set up virtualization in order to run
> various OS on a single machine. after watching, i decided
> i don't like that model. the argument is that it saves labor
> and materials costs and possibly even OS and application
> administration costs. I don't buy it except in uses such as
> school instruction or testing labs or some such. Seems to
> me that running multiple apps can be done on one box
> that runs one OS, and with more alacrity, as switching
> context for processes is faster than switching the entire OS
> context.

I can tell you how I use it.

I use vserver, which is extremely easy for Linux to do.  It's basically 
just an enhanced chroot - it doesn't create a new virtual kernel, nor 
emulate hardware.  (Therefore it does not require or benefit from hardware 
virtualization support, as far as I know - it's already faster than those 
approaches.)

If you think of vserver like chroot, but enhanced to provide virtual 
network interfaces and a more solid container system, then you'll gain the 
feeling that creating vservers is free.  Once you have that feeling, you 
may do what I do: When I have a web app to test, I don't want to make a 
mess of my main system.  So I just do 'newvserver', wait a minute, and 
then set it up in that jail.  Then I can access it by the IP address of 
that vserver.

I also use it for running software that has specific and annoying 
requirements for a base OS, like things that require RedHat-style systems 
or software that expects headers from old 1990s Debian.  I even bind-mount 
my home directory into the vservers with a modern enough bash etc. - that 
way, I don't copy files back and forth at all.

>   what i love and adore about virtualization is the promise
> that one can have a single virtualized machine and OS
> running on top of multiple hardware boxes, in the load-
> balanced cluster manner.

That's not really virtualization, it's called clustering, and packages for 
doing that have been available for a while.

>   hardware has always been the cheapest component of
> the enterprise IT stack (hardware, OS, application software,
> administration, training, data input, in that order cheapest
> to most expensive).

First of all, I don't agree.  If your enterprise doesn't have spare 
hardware lying around, then you have to spend human time to order it, wait 
for it, and get it.  That's a waste.

Secondly, I don't work in a large enterprise - I work in a small 
non-profit, and when I do things for myself or for other organizations I'm 
acting as myself, not as part of an enterprise.

My work machine has about 10 vservers running.  Machines may be cheap, but 
that many machines aren't all that cheap.  Space for 10 machines isn't 
easy to find, nor power for them being all that cheap.  Plus the ability 
to just have throwaway machines is great.  And the vservers "boot" (i.e., 
start syslog) in less than 0.5 seconds from a fresh install (Apache takes 
a few seconds, but the longest any of them take is 3 seconds).

So - for sysadmin testing, software testing, and software demoing to 
myself, the vserver virtualization technology is great for me.  Disposable 
machines, easy testing in different distributions, and no asking anyone 
for permission or moving my butt to plug in a power cable or press a 
switch on a KVM.  Oh, and it costs me no dollars.

-- Asheesh.

--
Once, adv.:
 	Enough.
 		-- Ambrose Bierce, "The Devil's Dictionary"