UML (Use Mode Linux), was: Re: [Jeff Covey @ Freshmeat] We Are Losing the Browser War

From: Stephen D. Williams (
Date: Wed Mar 28 2001 - 13:07:50 PST

Strata Rose Chalup wrote:
> So, is your laptop which you use as your central focus in life and
> work a production system or a tech end user system?
> I have an IBM X20 that is waiting for me to make up my mind whether
> to put Debian, Mandrake, or OpenBSD on it...

Use UML ( ) and you can
run any distribution of Linux at the same time.

OpenBSD is out until they port it to the Linux API (see below if that
doesn't make sense to you).
UML is one of the cooler hacks I've seen in a while. You know an OS api
is complete when you can fully and efficiently emulate a full, memory
and mode protected, true multitasking, fully binary compatible, flexible
OS like Linux on itself. I'll have to see if this can be done
recursively, which would be pure evil!

I wrote something about it on my list on Sunday:

I sent a previous message about UML here:

After reading the Linux Magazine article detailing how it works, etc.,
I'm interested, again, in playing with it. Especially since I'm
interested in kernel hacking. Downloading a root image, the kernel
patch (only needed for custom kernels), and executable now.

It's the Linux kernel ported to the Linux (i.e. Unix+) api. No native
assembly or anything. Should work on any Linux architecture. So much
for virtualized Linux on the IBM 370, any fast machine can now do the
same thing. It's supposed to be in the standard kernel tree as a
standard architecture soon.

Pretty slick how they emulate kernel/user mode, memory protection,
system calls, I/O interrupts, etc. It uses Linux threads to handle a
lot of context switching in it's threads, although only as many threads
are runnable as UML has virtual CPUs. Normally runs X using Xnest
(although obviously VNC could be used). It's biggest use is still
kernel development, but virtually hosted environments are becoming a
common use supposedly. UML doesn't have to run as root and of course
you could chroot it.

> _SRC
> Tom WSMF wrote:
> > As of Oct my prefernce was with Mandrake for an tech end user system
> > win NT for non tech end users and *BSD for an production system.
> --
> ========================================================================
> Strata Rose Chalup [KF6NBZ] strata "@"
> VirtualNet Consulting
> ** Project Management & Architecture for ISP/ASP Systems Integration **
> =========================================================================

Stephen D. Williams
43392 Wayside Cir,Ashburn,VA 20147-4622 703-724-0118W 703-995-0407Fax 

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