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

[H. G.]

On 3/26/08, Brian Gupta <brian.gupta at gmail.com> wrote:
>
> 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


Another interesting tidbit is SuSE's Yast utility, which works absolutely
flawless with Xen.  It's fully Xen aware, and presents the same facilities
you'd use for real installationsto Xen guests.  From as far back as
SLES 10.0, it's had flawless interoperability.  I'm the minimal
Debian breed of Linux user, but Yast kind of softened me up towards
SuSE.  I'm also interested in seeing what Enomalism is going to
bring to the table, though I could have sworn coming accross an
already function open source Xen web UI for Linux before.

Also, another vote for lighttpd.  Its right in the middle there, with
a good chunk of Apache's functionality (config file portability)
while maintaining strong performance (nginx's domain).

And heres a question especially for you, Brian, since you're our
resident Solaris guy: how come the Solaris Xen kernel refuses
to start on a "plain" x86 Linux hypervisor? (By "plain", I mean
not hardware backed.  This hypervisor isn't running on vT or
hardware virt. capable hardware).

Everytime I tried to create the Solaris guest domain,
xend commits hari-kari all the while sorrowfully whispering,
"Bad file descriptor".  Methinks the OpenSolaris wiki might
have to revise the suggestions that were posted concerning
running Solaris guests on Linux Xen hosts.

Either that or I'm out of pixie dust, too.

(Can anyone spare some?  I'll buy you beer...)