[Debian-User] Xen
One of the several reasons I left a large space on the hard drive was to
establish a Debian based Xen virtual machine. To do this Xen is
installed on top of the Debian kernel. The Debian distribution is
installed in a large partition so it can be added to in the future.
Other distributions and/or specific Debian applications (derived from
the primary distribution in the large partition) can be installed in
secondary and much smaller partitions. These secondary installations
(on their own partitions) are operated on by Xen in a way that
virtualies them, that is, executes their system calls, returns values,
and time slices their operation/execution so that many virtual systems
can be operating under Xen control of the interaction of the kernel
resources of the primary distribution. So it seems like there are many
separate systems running at the same time but there is only
virtualization occuring in time slices managed by Xen.
There are major advantages in setting up to a maximum of 64 partitions
lets say with each one taking a 2 Gig partition or less. For example,
this allows one to set up a variety of servers all virtualized. While
these servers are operating one can be examining the merits of several
desktops or applications one might find useful. These investigations
would be occuring concurrently (by time slices) and possibly involving
Internet traffic. Xen virtualization is more efficient than having one
traditional installation with a desktop, some favorite applications and
some servers running. For example, with Xen virtualization one server
application might be Apache web server. A second server application
might also involve Apache but one might be trying to work out certain
details such as the integration of perl, php, java, etc. While this is
going on Maxima could be running, a data acquisition application, and
so on could all be running in a virtual environment. Not only that,
these virtualized systems can also talk to each other. In general
virtualization (up to a point where the primary CPU, memory , and other
resources become exhausted) makes very efficient use of the hardware
resources so that a fair number of virtualizationa can run concurrently
with only a small dimishment in overall speed of operation. Much of the
single system operation is very inefficient when compared to virtualized
operation.
So that's where I am going. I was going to do this virtualization with
SuSE because I am fairly conversant with SuSE but I wanted to explore
servers and applications of all sorts that seem to be mostly on Debian
but not on SuSE. I want to run web servers and explore various
alternatives. I want to run math packages, electronic packages,
physics, and get into many applications that I have avoided because I
have not had this kind of capability and resoureces in order to
experiement with them without having to worry about back ups and
restores and all the kind of head aches that one can get into in trying
a new package for the first time or compiling just to find out that the
system is now dead. With virtualization, if you kill a virtualized
system you kill it. Just fix it or replace it or get rid of it.
Meanwhile everything else is buzzing along. There is nothing but an
endless wonderland of possibilities using virtualization and that's
where I hope I am going with Debian. By answering my questions you have
informed me and helped me appreciate what I can realize out of the
Debian distribution.
Hope this answers some of the questions I have been getting of the
nature, "just set up a basic system and add what you want and don't
worry about the entire distribution". I see Xen in conjunction with
Debian as a world of opportunity to evaluate, experiment, learn, and
blow things up without losing the primary system. I see only
opportunity to learn TeTex, Emacs, lilypond, hurd and find out about
numerous applications. But what I am really looking forward to is to
develop and compile and meet face to face the death knell of a dead
system while the rest of the virtual systems carry on without a concern.
What could be better????
BTW if anyone (I've seen a few Xen emails like the one where the AMD
package disappeared only to be replaced by a 686 based Xen package that
crashed) would like to set up a Debian Xen thread maybe we could help
one another as it seems that this virtualization thing does not interest
most people. But I think it's the future for computing.
Thanks to all and SNIP away at what you don't want and comment on what
you do want -- I welcome the dialog.
Thanks, Ted
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