qemu-nbd.texi

   1 @example
   2 @c man begin SYNOPSIS
   3 @command{qemu-nbd} [OPTION]... @var{filename}
   4
   5 @command{qemu-nbd} @option{-d} @var{dev}
   6 @c man end
   7 @end example
   8
   9 @c man begin DESCRIPTION
  10
  11 Export a QEMU disk image using the NBD protocol.
  12
  13 @c man end
  14
  15 @c man begin OPTIONS
  16 @var{filename} is a disk image filename.
  17
  18 @var{dev} is an NBD device.
  19
  20 @table @option
  21 @item --object type,id=@var{id},...props...
  22 Define a new instance of the @var{type} object class identified by @var{id}.
  23 See the @code{qemu(1)} manual page for full details of the properties
  24 supported. The common object types that it makes sense to define are the
  25 @code{secret} object, which is used to supply passwords and/or encryption
  26 keys, and the @code{tls-creds} object, which is used to supply TLS
  27 credentials for the qemu-nbd server.
  28 @item -p, --port=@var{port}
  29 The TCP port to listen on (default @samp{10809})
  30 @item -o, --offset=@var{offset}
  31 The offset into the image
  32 @item -b, --bind=@var{iface}
  33 The interface to bind to (default @samp{0.0.0.0})
  34 @item -k, --socket=@var{path}
  35 Use a unix socket with path @var{path}
  36 @item -f, --format=@var{fmt}
  37 Force the use of the block driver for format @var{fmt} instead of
  38 auto-detecting
  39 @item -r, --read-only
  40 Export the disk as read-only
  41 @item -P, --partition=@var{num}
  42 Only expose partition @var{num}
  43 @item -s, --snapshot
  44 Use @var{filename} as an external snapshot, create a temporary
  45 file with backing_file=@var{filename}, redirect the write to
  46 the temporary one
  47 @item -l, --load-snapshot=@var{snapshot_param}
  48 Load an internal snapshot inside @var{filename} and export it
  49 as an read-only device, @var{snapshot_param} format is
  50 'snapshot.id=[ID],snapshot.name=[NAME]' or '[ID_OR_NAME]'
  51 @item -n, --nocache
  52 @itemx --cache=@var{cache}
  53 The cache mode to be used with the file.  See the documentation of
  54 the emulator's @code{-drive cache=...} option for allowed values.
  55 @item --aio=@var{aio}
  56 Set the asynchronous I/O mode between @samp{threads} (the default)
  57 and @samp{native} (Linux only).
  58 @item --discard=@var{discard}
  59 Control whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap})
  60 requests are ignored or passed to the filesystem.  @var{discard} is one of
  61 @samp{ignore} (or @samp{off}), @samp{unmap} (or @samp{on}).  The default is
  62 @samp{ignore}.
  63 @item --detect-zeroes=@var{detect-zeroes}
  64 Control the automatic conversion of plain zero writes by the OS to
  65 driver-specific optimized zero write commands.  @var{detect-zeroes} is one of
  66 @samp{off}, @samp{on} or @samp{unmap}.  @samp{unmap}
  67 converts a zero write to an unmap operation and can only be used if
  68 @var{discard} is set to @samp{unmap}.  The default is @samp{off}.
  69 @item -c, --connect=@var{dev}
  70 Connect @var{filename} to NBD device @var{dev}
  71 @item -d, --disconnect
  72 Disconnect the device @var{dev}
  73 @item -e, --shared=@var{num}
  74 Allow up to @var{num} clients to share the device (default @samp{1})
  75 @item -t, --persistent
  76 Don't exit on the last connection
  77 @item -x NAME, --export-name=NAME
  78 Set the NBD volume export name. This switches the server to use
  79 the new style NBD protocol negotiation
  80 @item --tls-creds=ID
  81 Enable mandatory TLS encryption for the server by setting the ID
  82 of the TLS credentials object previously created with the --object
  83 option.
  84 @item -v, --verbose
  85 Display extra debugging information
  86 @item -h, --help
  87 Display this help and exit
  88 @item -V, --version
  89 Display version information and exit
  90 @end table
  91
  92 @c man end
  93
  94 @ignore
  95
  96 @setfilename qemu-nbd
  97 @settitle QEMU Disk Network Block Device Server
  98
  99 @c man begin AUTHOR
 100 Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.
 101 This is free software; see the source for copying conditions.  There is NO
 102 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 103 @c man end
 104
 105 @c man begin SEEALSO
 106 qemu(1), qemu-img(1)
 107 @c man end
 108
 109 @end ignore