[nylug-talk] After meeting tonight, anyone want to discuss XEN stuff? (Also a bunch of misc thoughts and notes).

[Brian Gupta]

Basically I am cutting my teeth, trying to learn XEN, and frankly
bring myself into the 21st century regarding the state of Linux and
x86 hardware. (As many of you know I am the "Solaris guy" in the
group). I built a dev server (quadcore x3220 2.4 GHz XEON, 8GB ECC
PC800 RAM, dual 1TB harddrives), and have been messing with various
distros. (CentOS 5.1, Ubuntu 7.10/8.04beta, Fedora 8/9beta)

Some misc lessons learned -- tidbits of info floating in my brain:

1) Closed source Nvidia drivers do not work with a XEN kernel. (Or, if
they do it requires stronger pixie dust than I had access to).
2) virt-manager is an emerging GUI tool that works with XEN, KVM, and
QEMU. It looks like it is loosely based on VMWares management GUI. It
seems that it is in various states of working out the box with XEN.
CentOS 5.1 seems to have the best out of box experience, but the
virt-manger is old and not as feature rich as other options.
3) virt-manager uses libvirt, which provides a common management
framework for opensource virtualization technologies.
4) QEMU is leveraged by XEN and KVM to provide some functionality.
5) virt-manager is probably not ready for primetime, thus learning the
CLI is probably still mandatory for getting started with XEN.
6) Hardy Heron 8.04 beta is pretty slick. Wait for Automatix support
before upgrading. Envy support is there, assuming you don't need XEN
support. (Anyone know if closed ATI drivers work on a XEN kernel).
7) KVM is the preferred virtualization technology for Ubuntu, and the
Linux kernel development team. XEN is out. (But XEN is also cross
platform, and not strictly tied to Linux implementations, as Solaris
and BSDes will also be providing Dom0 support) Dom0 = VMWare host. KVM
promises to be much easier for to use than XEN. It will probably
become the virtualization technology of choice for most desktop
oriented Linux distros.
8) You can change the allocation of resources to Dom0. IE: I can tell
my Dom0 that it only has two virtual CPUs, and 1GB or RAM. Dom0 seems
to be just a special priveledged management VM, as XEN really takes
over the metal.
9) SE-Linux is an annoyance when you are learning new technologies.
10) XEN on (Open)Solaris will be very attractive, but it's not yet
ready for production use. (ZFS integration will add exciting
snapshotting, cloning and other functionality).
11) Ubuntu and Gentoo Linux are the preferred platforms for Ruby on
Rails production deployment. (Mac OS X with the Textmate editor, being
the preferred development platform).
12) Ultramonkey is a very interesting load balancing, and HA set of
technologies that they WILL run in XEN.
13) There are some methods to convert back and forth between XEN and
EC2 images. You can build custom EC2 images that use a different
distro than what Amazon provides.
14) There is a new open-source management platform in closed beta
right now that lets you build your own EC2-like cluster/cloud.
http://www.enomalism.com/ Bonus - At least one of the project leads is
located in New York City. I'd love to hear them present at a future
NYLUG meeting.
15) Nginx is a very cool web server. Higher performance and less
resources than Apache. Not to mention easier to configure. Plus it is
a better reverse proxy load balancer than Apache's relatively new
mod-proxy-load balancing options.
16) XEN is not easy, and it's rapidly evolving. Plan to spend some
time cutting your teeth getting up to speed. (I am still in this
process). XEN is however, ready for production, if you put enough
homework into it. (It just may not be worth it unless you are
deploying it with some scale. It may be better to buy a VMWare or
XenSource shrink wrapped solution.) It all depends on how much your
time is worth, vs. how widely you plan to deploy. I see this changing
by the end of this year, but XEN management still requires alot of
homework.
17) MySQL proxy is nearing the point where it is ready for production
use. It's features outweigh it's newness. Check it out it's a very
nifty piece of tech.
18) PCI-Express is very different than PCI-X and PCI. PCI Express is
the future of most PC based expansion card technologies. (And there
are different kinds of PCI-Express cards x1 being the most common...
The various PCI technologies is definitely a worthy topic of
discussion.). Please excuse me for stating the obvious, but my last
couple rounds of personal tech buying have been laptops, it's been
about over 6 years since I built or bought my last "desktop".
19) DDR-3 is still way too expensive, and DDR2 is dirt cheap right
now. Buying 8GB of non-ECC RAM is very affordable. (I of course went
with ECC DDR2 PC800 RAM, which is pretty hard to find, but still
cheaper than DDR3 RAM)
20) The Dell PowerEdge 2950-III seems to be a very attractively priced
piece of server kit. (Not cheap enough for hobbyists though).
21) XEN has a neat technology that allows you to delegate hardware
resources down to individual PCI cards to DomU guest OSes.
(PCI-delegation). I can see this being useful down the road.
22) OpenSource RDP clients seem less performant than the Microsoft
ones. This may be due to my Linux video driver not being a fully
accelerated closed source driver.
23) Synergy is a very cool app. It allows you to share one keyboard
and mouse with multiple computers that each have their own phyical
screen. Best part about it, you can cut and paste between three or
more different OSes, and you can attach screen edges so the mouse
cursor will flow between the multiple OSes. (I am using it to share
one keyboard and mouse between WindowsXP, MacOSX, Linux and Solaris.)

Anyone interested in forming an unofficial NYLUG/New York XEN special
interest group?

Cheers,
Brian

P.S. - Feel free to ask for elaboration on any of the bullets, and add
anything to the discussion. Also note, that everything above is
strictly my opinion, and I can be educated otherwise.

-- 
- Brian Gupta

http://opensolaris.org/os/project/nycosug/

http://www.genunix.org/wiki/index.php/OpenSolaris_New_User_FAQ