Xen users - May 2008 - loop versus tap?

I noticed a vast improvement in stability and performance
when I replaced file: disk definitions with tap:aio:
in my virtual machines.

I think file: uses the /dev/loopN mechanism (right?).

Out of curiosity, could whatever underlying mechanism
(I have no idea what it is) that implements tap:aio
take the place of other uses of /dev/loopN on linux?

(Things like mounting a filesystem from an iso image
for instance).

Like I said, just idle curiosity...

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Hi Tom,

On Thu, May 29, 2008 at 8:51 PM, Tom Horsley <tom.horsley@att.net> wrote:
> I noticed a vast improvement in stability and performance
> when I replaced file: disk definitions with tap:aio:
> in my virtual machines.
>
That is the purpose of the block tap driver.

>
> I think file: uses the /dev/loopN mechanism (right?).
>
That''s right. It''s the loopback driver

>
> Out of curiosity, could whatever underlying mechanism
> (I have no idea what it is) that implements tap:aio
> take the place of other uses of /dev/loopN on linux?
>
I will defer this one to someone else, but give you something
that explains all about the block tap driver:
http://www.usenix.org/event/usenix05/tech/general/full_papers/short_papers/warfield/warfield_html/


Cheers,
Todd


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users