gpg: failed to create temporary file '/var/lib/lurker/.#lk0x57189100.hantslug.org.uk.32563': Permission denied
gpg: keyblock resource '/var/lib/lurker/pubring.gpg': Permission denied
gpg: Signature made Thu Mar 27 13:18:11 2008 GMT
gpg: using DSA key 20ACB3BE515C238D
gpg: Can't check signature: No public key
On Thu, Mar 27, 2008 at 12:03:17PM +0000, Tony Whitmore wrote:
>
> On Thu, 27 Mar 2008 11:30:04 +0000, Andy Smith <andy@???> wrote:
> > Ubuntu's Xen kernels are really poor. They are full of bugs and
> > crash continuously. I have found them unusable for domU in
> > production so I dread to think what dom0 is like. Maybe HVM is
> > better though.
>
> I've not had particular problems with them. We run Ubuntu 6.06 domUs and a
> 7.04 dom0 under PV for our web services and haven't had any crashes so far.
>
> > HVM is going to be quite slow compared to PV because of the emulated
> > block and net drivers.
>
> Hmm, Hugo suggested the other way round. :/
I probably didn't explain it very well, then. HVM will be faster
executing code (particularly kernel code), but slower running I/O. You
can speed up the I/O by adding PV drivers. virtio is the Linux
"native" PV implementation, and in theory is (or will be) supported by
qemu, Xen, VMWare and lguest.
> > I am not sure that there are any GPL PV drivers (for use in HVM) for
> > Linux -- Citrix and others sell proprietary ones I think. I have
> > skimmed through threads on xen-user that suggest James Harper has
> > some Windows PV drivers for block and net under development and
> > available for experimental use (GPL).
>
> I'll keep an eye on that. Unless I've misunderstood, surely the problem is
> as much which NICs the hypervisor knows how to present to the domUs as the
> drivers for the OS inside the domU itself?
To some extent, yes.
If you're talking paravirtual devices, the "NIC" presented by the
host container is a very odd beastie, and doesn't really resemble any
form of actual hardware. The PV driver then knows how to talk to that
device, and the overall design of the device and its corresponding
driver is aimed at maximal efficiency in data transfer.
Hugo.
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
--- "It was half way to Rivendell when the drugs began to take ---
hold" - Hunter S Tolkien, "Fear and Loathing
in Barad D?r"
