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Xen Hacker Interviewed
Drawoc Suomynona writes "The Xen virtual monitor is a new generation virtualization software that enable running multiple OSes at the same time with unprecedented level of performances. Manuel Bouyer was recently interviewed about his work porting Xen to the NetBSD operating system. The interview touches on why some consider Xen to be so good, how hard it is to integrate such a software package into an OS, and more."
>Linux is STILL for fags.
That's right, real men use BSD.
how Xen is different from vmware?
will this be useable to run windows inside OS X ?
if yes, what timeframe are we speaking of then ?
Anyone know Xen compares to jails in, say, FreeBSD? I've managed to setup a jail before where you do a "make world DESTDIR=/jaildir" and then do a jail on that directory, which gives someone the appearance of their own entire operating system. Is Xen similar to this, but allowing for many different operating systems rather than just another instance of the same one?
Also, glad to see the BSD section is at least still around. I can't seem to get it to show up on the Sections list, regardless of how I set it up.
Want to improve your Karma? Instead of "Post Anonymously", try the "Post Humously" option.
I see a ton of comments about not being able to use Xen to run Windows inside Linux, but no information the other way around...
Can Xen run Linux apps on my Windows installation? I am currently using Cygwin for that, and it's working okay, but some of my favorite apps are being run through SSH from my linux box to make all this happen.
I do too much in Windows to even dual-boot the system... I'd spend as much time booting as I would working/playing.
"If you make people think they're thinking, they'll love you; But if you really make them think, they'll hate you." - DM
I was expecting a comment like this:
Everybody should learn 8-bit 6502 assembly language because no computer requires more instructions than the 6502 chip has and even though it's only an 8-bit processor it can be expanded because it is easily expandable, plus you can put billions of miniature 6502 chips in computer in place of more expensive, proprietary, non-standards-based, non-open-source, capitalist pig processors. LOL BEOWULF CLUSTER XML FRAMEWORK.
For shame, Slahsdot. You're attempting to remotely make sense.
"Xen also offers virtual machine migration, where you freeze a Xen guest, move it to another machine and resume it there ... This also means that a similar environment for the guest has to exist on the remote system."
And if a similar environment is not available when it is moved, what happens to the state of the user? Would the hardware in use when the state is saved have to be exactly alike on the target machine?
Also, is the information retained on the backup until the full migration is completed and then deleted, or is deleting the backup during the migration optional, leaving a "frozen" and "restorable" state on the server? Is that a security risk if the workstation is compromised?
Stoned4Life
gen = new Random
Xen virtual machines can be "live migrated" between physical hosts without stopping them. During this procedure, the memory of the virtual machine is iteratively copied to the destination without stopping its execution. A very brief stoppage of around 60-300 ms is required to perform final synchronisation before the virtual machine begins executing at its final destination, providing an illusion of seamless migration. Similar technology is used to suspend running virtual machines to disk and switch to another virtual machine, and resume the first virtual machine at a later date.
(Quote from Wikipedia)
Reminds of when I was watching the old Max Headroom show, and Max would shuffle himself off of one monitor onto a display on a portable "processing unit" and somebody would pick him up and carry him away.
The higher the technology, the sharper that two-edged sword.
One more crippling bombshell hit the already beleaguered *BSD community when IDC confirmed that *BSD market share has dropped
Heh, I hope IDC wasn't so bad as they were with predicting itanium sales. We're lucky that this time they're using a oracle to check their predictions, I hope they used it with BSD.
We hear from those anal retentive, perfecto BSD users again.
so guest OSes that support that hardware can run with standard drivers. Xen creates a synthetic virtual device that's easier and more efficient to emulate than standard hardware. The downside is that there usually aren't any drivers for these virtual devices on most OSes since no one's written them yet. So if you go on Apple's web site and look for supported video hardware, you probably won't see Xen virtual video device. The other way of looking at it is Xen is the device maker and is supplying the driver directly rather than through Apple. And device makers don't always supply drivers for all OSes, at leat right away.
YHBT HAND
What I want from OS virtualization is to be able to run one guest OS on multiple hosts for redundency. I don't have (personally) much use for running multiple guest OSs on a host. I want to have a setup where if apache is in the middle of processing a request and a whole machine does, the request is still completed by the remaining machine. RAID1 for the whole damn machine. If you could do this will F/OSS on dirt cheap comodity hardware, the utility would be huge.
"You never know when some crazed rodent with cold feet might be running loose in your pants."
-Calvin
Well, at least the Troll's are still reading the BSD section!
May the Maths Be with you!
How about vs qemu? It seems Qemu has both a virtualizer and an emulator (the "qemu accelerator does the virtualizer part"), and can run un-modified OS's (like Win2K) just fine in the emulator mode.
I use QEMU quite a bit, to test our stuff on both linux and windwos. (yeh, I used vmware too after they matched qemu in price, and it worked fine too; but I saw no compelling reason to switch)
Curious how Xen compares to teh accelerated QEMU.
What? You like BDSM? Thanks for sharing, but... uhh... no thanks. Well, it probably is VERY manly.
The 'Net is a waste of time, and that's exactly what's right about it. - William Gibson
Are here and they rock. Zen has been in the making for some time now and is still not production ready. Anyone knows the differences between Zones and Xen?
BTW, Zones give near native performance - verified on production machines.
There's a dude who knows his stuff
Sure his code is interestingly enough
It will fulfill our wettest dreams
Taking multitasking to the extremes
Filling our machines with marshmallow fluff
11. Thou shall obey Da mighty Swing
Xen 3.0 on the newer Intel/AMD chips should be able to run Windows (or any other OS) without modification to the hosted OS.
But will apple support Xen so Mac OS X could be used under Xen? Thus far, I have not heard either yes or no WRT Xen.
I looked this up a while ago... Xen needs the HOST OS to be modified, at least with current CPUs. Fortunately, VMWare player if free as in beer, and it works. So, now I have a perfectly functioning Linux install which I couldn't do before (lack of WiFi support for my wireless chip). Xen is nice, but free VMWare is good and it works.
VMWare ESX Server 3 (currently in beta) will probably get as close as you can to having live fault tolarant servers. By sharing a storage such as SAN or iSCSI, it is able to instantly take over when it detects the failure of another physical box and should not lose any sessions or data. The other cool thing is that it can dynamically move a running virtual machine to a less loaded physical server. Still, it is not running two virtual machines simultaneously like you've described.
It requires changes to the guest Kernel. Dont expect microsoft to do this for us, they have nothing to gain by doing that.
---- Booth was a patriot ----
Yeah, but does it run linux?
Oh wait......
The truth shall always be free: Boris Floricic is Tron.
Clusters do exactly what you want, seemless failover. Virtualization isn't the term you are loking for.
Xen can essentially do this as well. Simply run a single Xen OS on multiple machines. If one fails then Xen will failit over to another physical machine. You aren't required to run many multiple OSes with Xen.
Most Xen performance numbers that one sees are taken while running in DomainO, not DomainU. Domain0 is going to be using the "native" device drivers ("native", because not using real IRQs, but Xen's Event system). The problem is, that's not where one runs real virtual machines, those are in DomainU's and those have significantly worse performance. an apples vs. oranges comparison is Xen Domain0 vs. Vmware Workstation. an apples to apples in that case is Xen Domain0 (as "host" of DomainUs) vs. Regular Linux (as host of Vmware worksation intances). an apples to apples is also DomainUs vs. Vmware Worksation.
That's not to say, DomainO benchmarks are pointless. In fact, you can do many cool things on Xen that if you don't care about multiple virtual machines, will work in your Domain0 with good performance.
Intel makes the chips. They have said quite clearly that the chips do support VT. People have displayed dmesg's showing that the CPUs do in fact report that they support it. Its just that some companies are shipping shitty boards with the functionality turned off, that doesn't mean that the CPUs don't support it.
. pdf
http://appleintelfaq.com/images/intel_vt_response
I personally have installed and ran generic Windows XP on Xen using the existing Intel chips with VT support. Performance basically sucks right now because Xen currently uses qemu to emulate bios/disk/network/video for these devices so with a lot of disk or network IO you can basically take the machine to its knees because it starts using up 100% cpu to emulate the IO.
This sig will make it clear that ANYONE can use this post for ANY purpose WITHOUT the written consent of the NFL.
Check out OpenBSD's CARP and use for your Apache or other httpd. Complete failover, with no down time if one fails and OpenBSD runs on old, cheap hardware without a hitch. The possibilities are endless! I've seem many great articles on it too. CARP isn't just for redundant firewalls with OpenBSD, it can be used for many other things too.