I understand that QSD is at an early stage of development and I'm sure you have plans to fix these things. Nevertheless here are my comments after trying to add an interop test with libnbd.
(1) Documentation! (Or complete lack of it ...) I had to ask Kevin how to construct the command line because several things were not obvious. In particular the --blockdev parameters only make sense if you're already used to constructing blockdev parameters (and these are, separately, not well-documented). And you have to supply the parameters in a particular order on the command line, else it doesn't work. (2) There seems to be no --pid-file option, so there's no way of knowing when the server is ready to accept connections, except to start QSD and then "sleep for a bit". (3) Seems to be no support for either serving requests over stdin/stdout (qemu-nbd also lacks this, but it's common for other NBD servers); or for systemd socket activation (qemu-nbd supports this). (4) Some parameter names changed between 5.1 and upstream. I understand that you're still finalizing the command line, so this isn't a problem in itself, but others who try to use QSD will need to be aware of it. 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/
