qemu-nbd(8)
NAME
qemu-nbd - QEMU Disk Network Block Device Server
SYNOPSIS
qemu-nbd [OPTION]... filename qemu-nbd -d dev
DESCRIPTION
Export a QEMU disk image using the NBD protocol.
OPTIONS
filename is a disk image filename, or a set of block driver options if
--image-opts is specified.
dev is an NBD device.
--object type,id=id,...props...
Define a new instance of the type object class identified by id.
See the qemu(1) manual page for full details of the properties
supported. The common object types that it makes sense to define
are the "secret" object, which is used to supply passwords and/or
encryption keys, and the "tls-creds" object, which is used to
supply TLS credentials for the qemu-nbd server.
-p, --port=port
The TCP port to listen on (default 10809)
-o, --offset=offset
The offset into the image
-b, --bind=iface
The interface to bind to (default 0.0.0.0)
-k, --socket=path
Use a unix socket with path path
--image-opts
Treat filename as a set of image options, instead of a plain
filename. If this flag is specified, the -f flag should not be
used, instead the '"format="' option should be set.
-f, --format=fmt
Force the use of the block driver for format fmt instead of auto-
detecting
-r, --read-only
Export the disk as read-only
-P, --partition=num
Only expose partition num
-s, --snapshot
Use filename as an external snapshot, create a temporary file with
backing_file=filename, redirect the write to the temporary one
-l, --load-snapshot=snapshot_param
Load an internal snapshot inside filename and export it as an read-
only device, snapshot_param format is
'snapshot.id=[ID],snapshot.name=[NAME]' or '[ID_OR_NAME]'
-n, --nocache
--cache=cache
The cache mode to be used with the file. See the documentation of
the emulator's "-drive cache=..." option for allowed values.
--aio=aio
Set the asynchronous I/O mode between threads (the default) and
native (Linux only).
--discard=discard
Control whether discard (also known as trim or unmap) requests are
ignored or passed to the filesystem. discard is one of ignore (or
off), unmap (or on). The default is ignore.
--detect-zeroes=detect-zeroes
Control the automatic conversion of plain zero writes by the OS to
driver-specific optimized zero write commands. detect-zeroes is
one of off, on or unmap. unmap converts a zero write to an unmap
operation and can only be used if discard is set to unmap. The
default is off.
-c, --connect=dev
Connect filename to NBD device dev
-d, --disconnect
Disconnect the device dev
-e, --shared=num
Allow up to num clients to share the device (default 1)
-t, --persistent
Don't exit on the last connection
-x NAME, --export-name=NAME
Set the NBD volume export name. This switches the server to use the
new style NBD protocol negotiation
--tls-creds=ID
Enable mandatory TLS encryption for the server by setting the ID of
the TLS credentials object previously created with the --object
option.
-v, --verbose
Display extra debugging information
-h, --help
Display this help and exit
-V, --version
Display version information and exit
SEE ALSO
qemu(1), qemu-img(1)
AUTHOR
Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>. This is
free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.
2016-12-01 QEMU-NBD(8)
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