1nbdkit-partitioning-plugin(1)       NBDKIT       nbdkit-partitioning-plugin(1)
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NAME

6       nbdkit-partitioning-plugin - create virtual disk from partitions
7

SYNOPSIS

9        nbdkit partitioning [file=]part1 [[file=]part2 [file=]part3 ...]
10                            [partition-type=mbr|gpt]
11

DESCRIPTION

13       "nbdkit-partitioning-plugin" is a plugin for nbdkit(1) which creates a
14       partitioned virtual drive from a list of one or more files each
15       containing single partitions.  The plugin concatenates the files
16       together and generates a virtual partition table so that NBD clients
17       see a single partitioned disk.
18
19       If you just want to concatenate files together (without adding a
20       partition table) use nbdkit-split-plugin(1).  If you want to select a
21       single partition from an existing disk, use nbdkit-partition-filter(1).
22       If you want to create a complete disk with a filesystem, look at
23       nbdkit-floppy-plugin(1), nbdkit-iso-plugin(1) or
24       nbdkit-linuxdisk-plugin(1).
25
26       The plugin supports read/write access.  To limit clients to read-only
27       access use the -r flag.
28
29   Partition table type
30       Using the "partition-type" parameter you can choose either an MBR or a
31       GPT partition table.  If this parameter is not present then:
32
33       number of files > 4
34           ⇒ GPT
35
36       else, total file size is larger than supported by MBR (approx. 2 TB)
37           ⇒ GPT
38
39       otherwise
40           ⇒ MBR (for maximum compatibility with clients)
41
42   Type of each partition
43       The type of each partition is controlled by a partition type byte (for
44       MBR) or a partition type GUID (for GPT).  This can be set using the
45       "mbr-id" or "type-guid" parameters respectively and affects the type of
46       all following files.
47
48   Padding and alignment
49       Partition sizes are automatically rounded up to a multiple of the 512
50       byte sector size.
51
52       Padding may be added between partitions to provide the best alignment.
53       This is controlled by the "alignment" parameter, which affects the
54       alignment of all following files.
55
56   Writing to the virtual disk
57       NBD clients may read and write freely to partitions.  Writes are
58       propagated through to the underlying files.
59
60       NBD clients may read from the virtual partition table, and padding
61       areas of the virtual disk.  When reading from padding areas, clients
62       will see zeroes.
63
64       NBD clients will get an I/O error if they try to change the virtual
65       partition table or padding areas.
66

EXAMPLES

68       From a bare filesystem stored in a file, create a virtual disk with a
69       single partition containing the filesystem:
70
71        nbdkit partitioning ext4fs.img
72
73       Create a virtual disk containing boot, swap and root partitions:
74
75        nbdkit partitioning \
76                   boot.img \
77                   mbr-id=0x82 swap.img mbr-id=default \
78                   root.img
79
80       This will not be bootable since the virtual partition table does not
81       contain a boot sector or boot loader.
82
83       Notice that the swap partition is bracketed by "mbr-id=0x82" to set the
84       MBR partition type byte to 0x82 (Linux swap) for the swap partition,
85       followed by "mbr-id=default" to set the MBR partition type byte back to
86       the default (0x83, Linux filesystem) for the remaining partition.
87
88       If file.raw has a size which is a multiple of 512 bytes then this is a
89       no-op because the partitioning plugin adds a partition table which is
90       then removed by nbdkit-partition-filter(1):
91
92        nbdkit --filter=partition partitioning file.raw partition=1
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PARAMETERS

95       [file=]FILENAME
96           One or more files containing partition data.
97
98           This parameter is required.
99
100           "file=" is a magic config key and may be omitted in most cases.
101           See "Magic parameters" in nbdkit(1).
102
103       partition-type=mbr
104           Add an MBR (DOS-style) partition table.  The MBR format is
105           maximally compatible with all clients.
106
107           If there are > 4 partitions then the first three files are mapped
108           to primary partitions, an extended partition
109           (https://en.wikipedia.org/wiki/Extended_boot_record) is created as
110           partition 4, and the files starting from the 4th will appear as
111           partition 5 and upwards.
112
113       partition-type=gpt
114           Add a GPT partition table.  Note that as well as the virtual
115           primary partition table added at the beginning of the disk, a
116           virtual secondary partition table is added at the end, as required
117           by GPT.  Also this adds a "protective MBR" as defined by the UEFI
118           spec so that old clients which don't understand GPT will ignore the
119           partitions.
120
121       alignment=N
122           Set the alignment of all following files to "N" bytes.  The default
123           alignment is 1M (2048 sectors).
124
125       mbr-id=0xN
126           Set the MBR type byte of all following files to "0xN".  Type bytes
127           are normally specified in hexadecimal, and you must use the "0x"
128           prefix to indicate this.
129
130       mbr-id=default
131           Set the MBR type byte back to the default, 0x83 which indicates a
132           Linux filesystem.
133
134       type-guid=GUID
135           Set the GPT partition type GUID of all following files to "GUID".
136
137       type-guid=default
138           Set the GPT partition type GUID back to the default,
139           "0FC63DAF-8483-4772-8E79-3D69D8477DE4" which indicates a Linux
140           filesystem.
141

LIMITS

143       Although this plugin can create GPT partition tables containing more
144       than 128 GPT partitions (in fact, unlimited numbers of partitions),
145       some clients will not be able to handle this.
146
147       Zero length partitions are not allowed and will cause nbdkit to exit
148       with an error when it starts up.
149
150       The sector size is fixed at 512 bytes.
151

FILES

153       $plugindir/nbdkit-partitioning-plugin.so
154           The plugin.
155
156           Use "nbdkit --dump-config" to find the location of $plugindir.
157

VERSION

159       "nbdkit-partitioning-plugin" first appeared in nbdkit 1.8.
160

SEE ALSO

162       nbdkit(1), nbdkit-file-plugin(1), nbdkit-floppy-plugin(1),
163       nbdkit-iso-plugin(1), nbdkit-linuxdisk-plugin(1),
164       nbdkit-partition-filter(1), nbdkit-split-plugin(1), nbdkit-plugin(3).
165

AUTHORS

167       Richard W.M. Jones
168
170       Copyright (C) 2018 Red Hat Inc.
171

LICENSE

173       Redistribution and use in source and binary forms, with or without
174       modification, are permitted provided that the following conditions are
175       met:
176
177       ·   Redistributions of source code must retain the above copyright
178           notice, this list of conditions and the following disclaimer.
179
180       ·   Redistributions in binary form must reproduce the above copyright
181           notice, this list of conditions and the following disclaimer in the
182           documentation and/or other materials provided with the
183           distribution.
184
185       ·   Neither the name of Red Hat nor the names of its contributors may
186           be used to endorse or promote products derived from this software
187           without specific prior written permission.
188
189       THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY
190       EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
191       IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
192       PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE
193       LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
194       CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
195       SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
196       BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
197       WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
198       OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
199       ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
200
201
202
203nbdkit-1.24.2                     2021-03-02     nbdkit-partitioning-plugin(1)
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