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AFAIK you can run FreeBSD and of course Windows on KVM The only requirement is your CPU's full virtualization support. A lot of CPU recently are capaple of har

by lamnk 17y ago

AFAIK you can run FreeBSD and of course Windows on KVM The only requirement is your CPU's full virtualization support. A lot of CPU recently are capaple of hardware virtualization, except low end processors.

lsc 17y ago
you can under HVM mode in xen, too. Full virtualization, though, in it's current state, is inferior to paravirtualization. Significantly so. This may change as hardware advances, but right now, you are much better off going with something that can run paravirtualized.
- lamnk 17y ago
  Full virtualization, though, in it's current state, is inferior to paravirtualization Do you have benchmarks to back it up ? Is performance the reason to choose Xen over KVM and other virtualization technologies for your hosting company ? Some benchmarks after quick google: http://virt.kernelnewbies.org/XenVsKVM http://virt.kernelnewbies.org/XenVsKVM
  - lsc 17y ago
    reliability even more than performance. KVM was not even close to production ready in '05. HVM mode under xen was also crap. I expect 3 year uptime; running some 'qemu with hardware support' (which really is what both xen hvm and quemu are) just could not deliver that at the time. Also emulated devices leave a much larger attack surface from the domU -> dom0 host. I am sure that KVM has improved a whole lot in the last few years, but most of the people using it seem to be using it for 'primarily use box as hardware, spin up a virtual to test something' (this, I think, is why the kernel guys like it so much... that is what they need, and KVM is much better than Xen if that is your use case.) I really need a 'dedicated virtualization server' - the hardware only exists to service virtuals. If I had some time, I'd do some benchmarks; I'd be interested to see what the backends the kernelnewbies bench uses... for example using tap: or phy: is sometimes an order of magnitude less bad than using file:// (of course, sometimes you get caching going in the dom0, and file:/ looks faster, but it's still a really bad idea.) I did start with FreeBSD jails, but switched to xen after I found just what a bad idea sharing pagecache is.

by lamnk 17y ago

lsc 17y ago

you can under HVM mode in xen, too. Full virtualization, though, in it's current state, is inferior to paravirtualization. Significantly so. This may change as hardware advances, but right now, you are much better off going with something that can run paravirtualized.

lamnk 17y ago
Full virtualization, though, in it's current state, is inferior to paravirtualization Do you have benchmarks to back it up ? Is performance the reason to choose Xen over KVM and other virtualization technologies for your hosting company ? Some benchmarks after quick google: http://virt.kernelnewbies.org/XenVsKVM http://virt.kernelnewbies.org/XenVsKVM
- lsc 17y ago
  reliability even more than performance. KVM was not even close to production ready in '05. HVM mode under xen was also crap. I expect 3 year uptime; running some 'qemu with hardware support' (which really is what both xen hvm and quemu are) just could not deliver that at the time. Also emulated devices leave a much larger attack surface from the domU -> dom0 host. I am sure that KVM has improved a whole lot in the last few years, but most of the people using it seem to be using it for 'primarily use box as hardware, spin up a virtual to test something' (this, I think, is why the kernel guys like it so much... that is what they need, and KVM is much better than Xen if that is your use case.) I really need a 'dedicated virtualization server' - the hardware only exists to service virtuals. If I had some time, I'd do some benchmarks; I'd be interested to see what the backends the kernelnewbies bench uses... for example using tap: or phy: is sometimes an order of magnitude less bad than using file:// (of course, sometimes you get caching going in the dom0, and file:/ looks faster, but it's still a really bad idea.) I did start with FreeBSD jails, but switched to xen after I found just what a bad idea sharing pagecache is.