From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56609) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gSzvU-0001CU-AY for qemu-devel@nongnu.org; Sat, 01 Dec 2018 02:42:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gSzvT-0003DW-CX for qemu-devel@nongnu.org; Sat, 01 Dec 2018 02:42:56 -0500 Date: Sat, 1 Dec 2018 07:42:45 +0000 From: "Richard W.M. Jones" Message-ID: <20181201074244.GF27120@redhat.com> References: <20181130220344.3350618-1-eblake@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181130220344.3350618-1-eblake@redhat.com> Subject: Re: [Qemu-devel] [PATCH for-4.0 00/14] nbd: add qemu-nbd --list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: qemu-devel@nongnu.org, jsnow@redhat.com, nsoffer@redhat.com, vsementsov@virtuozzo.com, qemu-block@nongnu.org On Fri, Nov 30, 2018 at 04:03:29PM -0600, Eric Blake wrote: > I note that upstream NBD has 'nbd-client -l $host' for querying > just export names (with no quoting, so you have to know that > a blank line means the default export), but it wasn't powerful > enough, so I implemented 'qemu-nbd -L' to document everything. > Upstream NBD has separate 'nbd-client' and 'nbd-server' binaries, > while we only have 'qemu-nbd' (which is normally just a server, > but 'qemu-nbd -c' also operates a second thread as a client). > Our other uses of qemu as NBD client are for consuming a block > device (as in qemu-io, qemu-img, or a drive to qemu) - but those > binaries are less suited to something so specific to the NBD > protocol. I tried it against nbdkit and it works (obviously): $ ./qemu-nbd -L exports available: 1 export: '' size: 67108864 flags: 0x61 ( trim zeroes ) What I couldn't work out is how to connect to other hosts. It's possible to add -p or -k to change the localhost port number or to use a Unix domain socket (and I checked both work). However can we connect to remote hosts? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html