qemu-nbd 2.10.0(Debian 1:2.10+dfsg-0ubuntu1) Written by Anthony Liguori. Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Usage: qemu-nbd [OPTIONS] FILE QEMU Disk Network Block Device Server -h, --help display this help and exit -V, --version output version information and exit Connection properties: -p, --port=PORT port to listen on (default `10809') -b, --bind=IFACE interface to bind to (default `0.0.0.0') -k, --socket=PATH path to the unix socket (default '/var/lock/qemu-nbd-DEVICE') -e, --shared=NUM device can be shared by NUM clients (default '1') -t, --persistent don't exit on the last connection -v, --verbose display extra debugging information -x, --export-name=NAME expose export by name -D, --description=TEXT with -x, also export a human-readable description Exposing part of the image: -o, --offset=OFFSET offset into the image -P, --partition=NUM only expose partition NUM General purpose options: --object type,id=ID,... define an object such as 'secret' for providing passwords and/or encryption keys -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>] specify tracing options --fork fork off the server process and exit the parent once the server is running Kernel NBD client support: -c, --connect=DEV connect FILE to the local NBD device DEV -d, --disconnect disconnect the specified device Block device options: -f, --format=FORMAT set image format (raw, qcow2, ...) -r, --read-only export read-only -s, --snapshot use FILE as an external snapshot, create a temporary file with backing_file=FILE, redirect the write to the temporary one -l, --load-snapshot=SNAPSHOT_PARAM load an internal snapshot inside FILE and export it as an read-only device, SNAPSHOT_PARAM format is 'snapshot.id=[ID],snapshot.name=[NAME]', or '[ID_OR_NAME]' -n, --nocache disable host cache --cache=MODE set cache mode (none, writeback, ...) --aio=MODE set AIO mode (native or threads) --discard=MODE set discard mode (ignore, unmap) --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap) --image-opts treat FILE as a full set of image options See <http://qemu.org/contribute/report-a-bug> for how to report bugs. More information on the QEMU project at <http://qemu.org>.