Goswin von Brederlow a écrit : > Gunnar Wolf <[EMAIL PROTECTED]> writes: > >> Goswin von Brederlow dijo [Tue, Jul 15, 2008 at 11:10:30PM +0200]: >>>> I don't think that any of the alternatives are valid candidates yet: >>>> - Linux-Vserver, OpenVZ: clearly not the same use case. >>>> - Virtualbox, qemu: poor performance under some workloads. >>> Unusable for production work. Emulation is just too slow. The group of >>> people that can live with that much slow down compared to xen is >>> miniscule. >> Just to state the obvious: I understand your lines applie to >> virtualbox and qemu, not to linux-vserver, which is completely usable >> for production work - although it's a completely different approach, >> completely useless to people who really want seemingly independent >> full machines (i.e. different OSs or kernel features). > > yes, obviously. :) > >>>> - KVM: is very promising but is it really a valid alternative *now* >>>> for current Xen users? >>> KVM needs hardware support and even then its I/O is slower. It also >>> deadlocks the I/O under I/O load from time to time. >>> >>> I could live with the I/O slowdown but nothing will make hardware >>> magically appear. >> Please explain further on this. Do you mean that xen can run >> paravirtualized hosts without the hardware features (i.e. the lesser >> CPUs sold nowadays) while kvm does require VMX/SVM? > > Yes, xen with paravirtualized hosts runs on cpus without hardware > virtualization. > >> I have not done extensive testing yet (I'm a newbie to both >> approaches), but I don't feel the slowdown you mention when under kvm. > > The "normal" kvm io uses the qemu device emulation and is dead slow > and unsecure. As such it is pretty much out of the question for > production work. > > But kvm can also use the virtio drivers that raise the network speed > to slightly over 40MB/s. Disk speed is slower but that might just be > my laptops disk.
With latest kvm version (71), I am able to reach 174 MB/s throughput on the virtio network interface, so it is now comparable to Xen. > Now with xen on the other hand I get up to 180MB/s throughput on the > network interface. > >> Greetings, > > MfG > Goswin > > -- .''`. Aurelien Jarno | GPG: 1024D/F1BCDB73 : :' : Debian developer | Electrical Engineer `. `' [EMAIL PROTECTED] | [EMAIL PROTECTED] `- people.debian.org/~aurel32 | www.aurel32.net -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]