Red Hat went out public to say loudly about Xen and their plans about that. There is a nice virtualization introduction demo (you need Flash to see it) on their openvirtualization.com site. I have just noticed that if you change the word "Xen" to "OpenVZ", and remove anything concerning "hypervisor", it would be quite an accurate description of what OpenVZ is and what it can do for you. So I welcome everybody to see that demo.
Still, Xen is a bit different. Say, you can not load kernel modules from inside an OpenVZ VPS, or use different kernels for diffrerent VPSs on the same box — but this is possible with Xen.
That leads to the question: what if you need some special kernel module in OpenVZ? The answer is: if it is a device driver and you want to use that device from within one VPS, it is possible (look for '--devnodes' and '--netdev_add' in vzctl man page). If you want to use some special stuff like, say, iptables module, from within a VPS — such module needs to be "virtualized" first (many iptables modules are already virtualized, so you can actually use them from a VPS).
By the way, speaking of that, recently Jason Stubbs, a Gentoo developer, send us a patch to virtualize ipt_REDIRECT kernel module. His work will appear soon in the kernel and vzctl we will release next week. Nice job, Jason!
Still, Xen is a bit different. Say, you can not load kernel modules from inside an OpenVZ VPS, or use different kernels for diffrerent VPSs on the same box — but this is possible with Xen.
That leads to the question: what if you need some special kernel module in OpenVZ? The answer is: if it is a device driver and you want to use that device from within one VPS, it is possible (look for '--devnodes' and '--netdev_add' in vzctl man page). If you want to use some special stuff like, say, iptables module, from within a VPS — such module needs to be "virtualized" first (many iptables modules are already virtualized, so you can actually use them from a VPS).
By the way, speaking of that, recently Jason Stubbs, a Gentoo developer, send us a patch to virtualize ipt_REDIRECT kernel module. His work will appear soon in the kernel and vzctl we will release next week. Nice job, Jason!


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If only I had some figures that reveal just how many lower end machines are sold by say... Dell... vs. higher end machines.
Heck, I've been talking to Virtuozzo's sales department some (because they don't do business any other way) to see how much their product costs. In their literature they boast "500+ customers".
Contrast Virtuozzo's "500+ customers" (and it has been around for over 5 years)... to say... how many OpenVZ downloads there are every single day. While I have no figures on the number of OpenVZ downloads... at some point (if it hasn't already) I would assume it would pass the 500+ downloads PER DAY mark.
That isn't to say that people don't want to buy Virtuozzo... or VMware... or use Xen... but there are plenty of "lower hanging fruit" that simply wouldn't consider Virtuozzo or VMware (because of the cost and licensing) and simply don't want or need Xen.
Again, I use that in support of the idea that Red Hat (and SuSE and everyone else) should make sure all virtualization schemes run well on their systems... and I would especially like to see OpenVZ working well in Xen.