View source for Virtualization


== Virtual Madness ==
This section is dedicated to lightweight Linux virtualization and lightweight Linux. It does not pretend to be exhaustive, but documents some (if not all) of my investigations into this area. As a former consumer product designer, this is an area of great interest to me, because I'm always thinking about applications for these technologies.

=== OpenVZ ===
I've used OpenVZ VPS (outside of Level(3)) for some time now. It's easy to see why OpenVZ is popular with providers. Administration is a breeze. I'm using it all the time in the lab now. The extremely fast and easy spinup/takedown allows fully leveraging virtualization for development and helps keep distros installed on bare metal clean and pristine. See [[OpenVZ|the wiki page I created for OpenVZ]] with instructions for users and installers.

=== UML - User Mode Linux ===
This is a very freaky piece of work. You can run Linux inside of Linux, even if you're not root. You can be root inside your UML instance, but of course you can't violate the parent instance's permissions. This work definitely has its uses, and will take a place in my toolkit, but there's still lots of quirky stuff with it.

In particular, you can't mix 32 bit systems with 64 bit systems. In my initial experiments, I had lots of trouble with the 64 bit stuff. I set up a 32-bit OpenVZ container of CentOS 6.3, and was able to run it inside that despite many error messages. The filesystem took up lots of space too (as a single file in the host instance). Here's what a Debian squeeze 6.0 32bit instance looked like:
<pre>
The "filesystem":
-rw-r--r-- 1 root root 1073741824 Mar 14 03:08 Debian-Squeeze-x86-root_fs  (yup, that's one gig)
root@(none):~# df
Filesystem           1K-blocks      Used Available Use% Mounted on
tmpfs                    14896         0     14896   0% /lib/init/rw
tmpfs                    14896         0     14896   0% /dev/shm
rootfs                 1032088    231476    748184  24% /
tmpfs                   786432         0    786432   0% /tmp
root@(none):~# uname -a
Linux (none) 2.6.24-rc7-dirty #97 Mon Jan 7 11:18:24 EST 2008 i686 GNU/Linux
</pre>

This thing is developing rapidly, so these links may go bad quickly!

*Here's the sourceforge page: http://user-mode-linux.sourceforge.net/
*Here's the official source of kernels and filesystems: http://uml.devloop.org.uk/
*This is a "lab" that helps you understanding how networking works in UML http://www.ida.liu.se/~TDDI09/labs/UML%20-%20User%20Mode%20Linux.pdf

I must admit I am mesmerized and/or obsessed with this "thing" as of this writing. It's a piece of work. I even bought the book (used on Amazon).

=== Docker ===
This is new to me and I haven't delved into it, but it looks on the surface to be something similar to UML...

http://www.docker.io/

The article that drew my attention is at:

http://www.activestate.com/blog/2013/06/solomon-hykes-explains-docker

=== BusyBox ===
It sounds like a "kids toy", but [http://www.busybox.net BusyBox] is a lightweight Linux distro oriented toward embedded systems. It's used in many consumer "smart" devices, and in many SOHO (Small Office/Home Office) and consumer router/switches. There is a [http://fs.devloop.org.uk/filesystems/BusyBox-1.13.2/ UML port] of BusyBox. There is a version that has been ported to the Java VM, so you can have a BusyBox instance [http://www.busybox.net/live_bbox/live_bbox.html running inside your browser]! Analog Devices has a constellation/ecosystem of developers for their [http://blackfin.uclinux.org/gf/ Blackfin] embedded processors for which there is a BusyBox port. There are likely many others. The port of Debian Linux to the ARM processor preceded the meteoric growth of commodity ARM-based tablets, smartphones, and devices (like Raspberry PI) and so is a heavier-weight alternative to BusyBox that looks more appealing as embedded devices scale.

=== KVM/QEMU on Fedora in Lab ===

* Prototype for new ip1.idc1 / ip1.adc1 hardware upgrade

'''Notes'''

* RDP/VNC is not viable for management
* Using ssh X tunneling to [various flavors of] Linux on desktop via Virtual Box




== Links to this Wiki ==
OpenVZ
KVM