2017-07-27 20:18 GMT+08:00 Richard W.M. Jones <rjones@redhat.com>:
On Thu, Jul 27, 2017 at 06:34:13PM +0800, lampahome wrote:
> I can mount qcow2 img to nbd devices through guestfish or qemu-nbd
>
> I'm curious about which performance is better?

They do quite different things, they're not comparable.

Can you specifically give the commands you are trying?  We might be
able to give more sensible advice.

Rich.

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guestfish:
guestfish --rw -a demo.qcow2 -m /dev/nbd0

qemu-nbd:
qemu-nbd -c /devnbd0 demo.qcow2

I just want to mount demo.qcow2 to a device