Re: [Libguestfs] performance between guestfish and qemu-nbd

On Fri, Jul 28, 2017 at 12:23:04AM +0800, lampahome wrote: > 2017-07-27 20:18 GMT+08:00 Richard W.M. Jones <rjones(a)redhat.com&gt;: > > > 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. > > guestfish: > guestfish --rw -a demo.qcow2 -m /dev/nbd0 > > qemu-nbd: > qemu-nbd -c /dev/nbd0 demo.qcow2 These don't do the same thing. In fact the guestfish command doesn't work at all. > I just want to mount demo.qcow2 to a device Still unclear. You want to export demo.qcow2 as NBD? Use qemu-nbd. You want to mount demo.qcow2 on the local filesystem? (This doesn't involve NBD.) Use: mkdir /tmp/mnt guestmount --rw -a demo.qcow2 -i /tmp/mnt Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~ rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/

mkdir /tmp/mnt guestmount --rw -a demo.qcow2 -i /tmp/mnt