On Sunday 23 April 2006 20:31, jdd sur free wrote:

Hello :-)

I use vmware for testing purpose (for example new 10.1). I do this for ages, now (was vmware 2.0)

VMWare (currently) emulates all a new 386 compatible system, but allows the guest to use the CPU natively. There is some overhead associated with emulating the system.

but vmware is dawn slow. Bochs is worst in this respect.

Bochs emulates both the system and the CPU. Much more overhead, much slower.

Is Xen able to do the same job? I could never understand what Xen is good for :-(((

Xen hosts and guests (more properly Priviledged and Unpriviledged Domains) are specially modified to know they are running under the Xen hypervisor (hence you can't run Windows). Because of this the host/guest runs natively on the CPU, and doesn't require the level of system emulation that VMWare does. This means it runs significantly closer to native speed. With the new Vanderpool or upcoming Pacifica tech from Intel and AMD respectively, the host/guest will not need to be modified for Xen manage them. Right now, Xen is excellent provided you are in an OSS environment. i.e. an ISP can offer individual virtual linux machines to customers. They can then aggregate, manage, and migrate those on large servers, maximising the resource usage of those machines, and scaling their servers and network in a controlled manner. Until Vanderpool and Pacifica are more widely deployed, it's a much tougher sell for individual users. Traditionally the great feature of VMWare (for me at least) was the ability to run legacy Windows apps in an OSS system, and no Wine is frequently not the answer to that conundrum. If I'm limited to OSS in my guests, then why not just run it on my host? There are cases where it is useful, i.e. testing environments etc, but it very much depends on your usage. -- Steve Boddy

Stephen Boddy wrote:

If I'm limited to OSS in my guests, then why not just run it on my host? There are cases where it is useful, i.e. testing environments etc, but it very much depends on your usage.

E.g., to provide security environments. E.g., one Xen host can be a Web server on a firewall, thus implementing a virtual DMZ. This is very interesting for SOHO and private home installations that don't want to establish real DMZs with real machines. Joachim -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Joachim Schrod Email: jschrod@acm.org Roedermark, Germany

Stephen Boddy wrote:

On Tuesday 25 April 2006 01:40, Joachim Schrod wrote:

...

Stephen Boddy wrote:

...

If I'm limited to OSS in my guests, then why not just run it on my host? There are cases where it is useful, i.e. testing environments etc, but it very much depends on your usage.

E.g., to provide security environments. E.g., one Xen host can be a Web server on a firewall, thus implementing a virtual DMZ. This is very interesting for SOHO and private home installations that don't want to establish real DMZs with real machines.

Yes it's an interesting concept. I was thinking of something very similar using vmware in pre-Xen days. But the problem is securing Xen whilst giving access to the toys we all want in our desktop user experience.

You're right; that's why I proposed to use Xen for servers. :-) It is quite clear that Xen is not a replacement for VMware. For example, I have roughly 20-30 VMware instances on my personal system (various customer environments, test installations of other operating systems, development/compile environments, test environments, etc.) But I have only two or three Xen servers; and none of them for interactive usage. Nevertheless, they are much more lightweight than VMware is. Joachim -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Joachim Schrod Email: jschrod@acm.org Roedermark, Germany

Jerry Feldman wrote:

On Tuesday 25 April 2006 9:26 am, Joachim Schrod wrote:

...

You're right; that's why I proposed to use Xen for servers. :-)

It is quite clear that Xen is not a replacement for VMware. For example, I have roughly 20-30 VMware instances on my personal system (various customer environments, test installations of other operating systems, development/compile environments, test environments, etc.) But I have only two or three Xen servers; and none of them for interactive usage. Nevertheless, they are much more lightweight than VMware is. Take a look at Virtual Iron. They are working with Xen. http://www.virtualiron.com/

Yes, that might be an interesting solution -- if they would give out more information. But at least they need to support Windows (announced for Sep 06, but surely some issues need to be shaken out), and also other operating systems like Solaris and BSDs. In addition, they should provide technical information and data sheets without the need to sign up with address and personal information. They are not established enough to play such silly games. Look at the form that one should fill out just to get information about their products, and compare that with VMware's site -- Virtual Iron has a some way to go before they get me as customer. For example, their Web site did not provide any information about snapshot and cloning capabilities (which are essential for me), only some trademarked terms about capabilities that are not explained at all. From a first glance, they address more the workload issues of data centers, and not testing environments. Joachim -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Joachim Schrod Email: jschrod@acm.org Roedermark, Germany

Ken Schneider wrote:

On Wed, 2006-04-26 at 12:09 +0200, Joachim Schrod wrote:

...

Jerry Feldman wrote:

...

Take a look at Virtual Iron. They are working with Xen. http://www.virtualiron.com/

In addition, they should provide technical information and data sheets without the need to sign up with address and personal information. They are not established enough to play such silly games.

Then do what I did and enter false information, You will still get the info.

I.e., I shall engage in playing silly games, too. I might do so, if I would have information that their product is really worth it, by 3rd party recommendations that come from practical experiences and not just from reading some white papers. That's the sense of "established enough" that I mentioned above. See, I'm the CEO of an IT consulting company. It is my opinion that a business _must_ tell its potential customers what it can deliver -- after all, we want to sell something that's good, so why shouldn't we publically tell about it? I prefer to do business with companies that have similar behaviour. E.g., there is VMware who are well-behaving business partners, with an excellent product, good service, and reasonable prices. There is also Virtuozzo, for hosting and data center solutions. (OpenVZ if you want to go the Open Source route, though without service contracts.) For the low end, there is Xen, as part of SUSE. And now Virtual Iron appears in that niche market; an additonal add-on solution, combined with a worse business attitude than their competitors. Well, they must be much much better to spawn lots of interest. Shying potential customers away is not good business sense; that's a truism I learned to appreciate in the 15+ years that I'm leading companies. I wish all the luck to Virtual Iron as a company, they will need it. Joachim -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Joachim Schrod Email: jschrod@acm.org Roedermark, Germany