[libvirt] PATCH: Disable QEMU drive caching

Daniel Veillard veillard at redhat.com
Fri Oct 10 09:45:51 UTC 2008

On Thu, Oct 09, 2008 at 12:03:28PM -0500, Anthony Liguori wrote:
> I've been persuaded.  Relying on the host's integrity for guest data  
> integrity is not a good idea by default.  I don't think we should use  
> cache=off to address this though.  I've sent a patch and started a  
> thread on qemu-devel.  Let's continue the conversation there.

  Well, it's really good to be able to expect a good default behaviour
but that doesn't mean there shouldn't be a user setting to activate
or deactivate caching explicitely. It will still be avaialble at the
QEmu level, I think it makes some sense in other environment even
if that's not applicable for a container based virtualization.

  I think we should still provide an optional flag at the libvirt
device XML description to indicate caching on the hypervisor preference
for a device. Off by default of course.


Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/

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