[tlug] virtualization (was "Running multiple web development environments on one machine")

[Micheal E Cooper <mcooper@example.com>]

Keith Bawden wrote:
> Hello,
>
> Grab a copy of VMware and install as many "test" environments as you 
> want (or have the RAM/HDD for). That way you can test in the same 
> environment (even same distro) as your clients hosted one.
>
> I say VMware because it is quite cheap and easy to use, and will allow 
> you to get up and running in short order. You will also be able to 
> install Windows XP so you can test your work out under IE without 
> needing to reboot.
>
> If VMware is not for you you could try qemu, or UML.
>
> Regards, Keith
>
>   
Are VMware, qemu, and UML really that easy to use now? What about Xen? 
RH website says they were going to include it as integral part of RHEL5 
and FC5, but the project is changing too quickly. I would really like to 
try out virtualization solutions in the near future, but I must admit 
that I am a bit intimidated... and I would need to buy a machine capable 
of it.

The O'Reilly Useractive courses seem to be taught with each student 
getting root on a virtual machine. I am embarrassed to admit that I am 
taking these courses, but I was really in a rut for a while, and I had a 
gap between my present IT job and my IT education that left me out of 
touch with a lot of details and rusty. The courses are helping me get 
back into the studying frame of mind. But the interesting thing here is 
the way the sandbox for users is set up.

From an explanation I wrote to my よき先輩:
------
You log into a DMZ server at useractive named 'hot' or 'cold', then
you use an ssh wrapper command ('hottub') to connect to one of the 'hottub'
servers (there are at least two). The user home directories are all on
NFS shares, it seems. Then from there it gets more interesting. There
are a large number of 'bubble' servers to which you can connect from
the 'hottub' servers. The metaphor is wonderful, because the hot and 
cold water go in the hottub, and you must get in the hottub before you 
can play with the bubbles.

It feels just like you are using separate machines, but they must be
virtual machines, because the first time that you ssh into
one (again through a wrapper called 'bubble' that hooks you up with an
available bubble server named something like bubble17) it takes a
minute or so to boot. You do exercises through ssh, going back and forth 
between
your bubble and the hottub.

Here comes the fun part: in the section that I just did, which goes
through manually setting an IP address and default gateway and
rebooting, it uses a command called 'console,' which is a wrapper for
screen, and it gives you the same access as if you were sitting at the
console of the (virtual) hardware itself. You reboot, and you watch most 
of the
shutdown and boot processes through this ssh->ssh->screen connection.
It is pretty neat, or at least I thought it was. Might be cold oatmeal
to you, but I felt that it really demonstrated the kind of plain but
useful training tools that smart people can set up with basic open
source tools. Nothing flashy or gimmicky, with animation and cheesy 
models and business jargon about TCO. Just a clean, basic, and lucid 
educational environment.
------

On an aside (and a much less-important query), I wonder how long it will 
take folks to get virtualization on the new intelMacs going, so that one 
machine is running OSX, Windows, and Linux all at the same time?

mec

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