Re: [Xen-users] which disk/tap device to use for xen?

["Dylan Martin" <dmartin@xxxxxxxxxxxx>]

I've been working on this same thing.  I think the answer is: if you
have to ask, the answer is 'aio', which is async.

There's a doc describing the various tap drivers (dig.. dig..)  here
http://wiki.xensource.com/xenwiki/blktap

The different drivers are not well documented or tested.  By tested I
mean, not very many people use them and talk about them on this list.
EG try searching this list archives for 'tap:ram' and you'll get two
hits, this email being the 2nd.

So, unless you're really into a particular feature, want to write and
support your own driver etc... you want 'aio'.

On Sat, Jan 10, 2009 at 11:06 AM, Michael Monnerie
<michael.monnerie@xxxxxxxxxxxxxxxxxxx> wrote:
> Hi, the docs on
> http://tx.downloads.xensource.com/downloads/docs/user/
> do not mention at all which tap: should be used for xen. I've ggogled
> that file: is bad/ugly/horrible, and you should use tap:aio instead. But
> my blktapctrl (openSUSE 11.1, kernel 2.6.27.9) can do more:
>
> BLKTAPCTRL[6249]: blktapctrl.c:797: Found driver: [raw image (aio)]
> BLKTAPCTRL[6249]: blktapctrl.c:797: Found driver: [raw image (sync)]
> BLKTAPCTRL[6249]: blktapctrl.c:797: Found driver: [vmware image (vmdk)]
> BLKTAPCTRL[6249]: blktapctrl.c:797: Found driver: [ramdisk image (ram)]
> BLKTAPCTRL[6249]: blktapctrl.c:797: Found driver: [qcow disk (qcow)]
> BLKTAPCTRL[6249]: blktapctrl.c:797: Found driver: [qcow2 disk (qcow2)]
> BLKTAPCTRL[6249]: blktapctrl.c:797: Found driver: [ioemu disk]
> BLKTAPCTRL[6249]: blktapctrl.c:797: Found driver: [raw image (cdrom)]
>
> So I guess possible would be tap:aio, tap:sync,and the others are
> specialized. But which one is the "best" to take. Stability/Reliability
> is most important, performance 2nd most.
> Has anyone got a hint or link to docs? I'd be interested in qcow
> documentation also.
>
> mfg zmi
> --
> // Michael Monnerie, Ing.BSc    -----      http://it-management.at
> // Tel: 0660 / 415 65 31                      .network.your.ideas.
> // PGP Key:         "curl -s http://zmi.at/zmi.asc | gpg --import"
> // Fingerprint: AC19 F9D5 36ED CD8A EF38  500E CE14 91F7 1C12 09B4
> // Keyserver: wwwkeys.eu.pgp.net                  Key-ID: 1C1209B4
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
>

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