virt-format(1)

1virt-format(1)              Virtualization Support              virt-format(1)
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NAME

6       virt-format - Erase and make a blank disk
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SYNOPSIS

9        virt-format [--options] -a disk.img [-a disk.img ...]
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WARNING

12       Using "virt-format" on live virtual machines, or concurrently with
13       other disk editing tools, can be dangerous, potentially causing disk
14       corruption.  The virtual machine must be shut down before you use this
15       command, and disk images must not be edited concurrently.
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DESCRIPTION

18       Virt-format takes an existing disk file (or it can be a host partition,
19       LV etc), erases all data on it, and formats it as a blank disk.  It can
20       optionally create partition tables, empty filesystems, logical volumes
21       and more.
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23       To create a disk containing data, you may be better to use
24       virt-make-fs(1).  If you are creating a blank disk to use in
25       guestfish(1), you should instead use the guestfish -N option.
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27       Normal usage would be something like this:
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29        virt-format -a disk.qcow
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31       or this:
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33        virt-format -a /dev/VG/LV
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35       disk.qcow or /dev/VG/LV must exist already.  Any data on these disks
36       will be erased by these commands.  These commands will create a single
37       empty partition covering the whole disk, with no filesystem inside it.
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39       Additional parameters can be used to control the creation of
40       partitions, filesystems, etc.  The most commonly used options are:
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42       --filesystem=[ext3|ntfs|vfat|...]
43           Create an empty filesystem ("ext3", "ntfs" etc) inside the
44           partition.
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46       --lvm[=/dev/VG/LV]
47           Create a Linux LVM2 logical volume on the disk.  When used with
48           --filesystem, the filesystem is created inside the LV.
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50       For more information about these and other options, see "OPTIONS"
51       below.
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53       The format of the disk is normally auto-detected, but you can also
54       force it by using the --format option (q.v.).  In situations where you
55       do not trust the existing content of the disk, then it is advisable to
56       use this option to avoid possible exploits.
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OPTIONS

59       --help
60           Display brief help.
61
62       -a file
63       --add file
64           Add file, a disk image, host partition, LV, external USB disk, etc.
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66           The format of the disk image is auto-detected.  To override this
67           and force a particular format use the --format=.. option.
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69           Any existing data on the disk is erased.
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71       -a URI
72       --add URI
73           Add a remote disk.  See "ADDING REMOTE STORAGE" in guestfish(1).
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75       --blocksize=512
76       --blocksize=4096
77       --blocksize
78           This parameter sets the sector size of the disk image.  It affects
79           all explicitly added subsequent disks after this parameter.  Using
80           --blocksize with no argument switches the disk sector size to the
81           default value which is usually 512 bytes.  See also
82           "guestfs_add_drive_opts" in guestfs(3).
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84       --filesystem=ext3|ntfs|vfat|...
85           Create an empty filesystem of the specified type.  Many filesystem
86           types are supported by libguestfs.
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88       --filesystem=none
89           Create no filesystem.  This is the default.
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91       --format=raw|qcow2|..
92       --format
93           The default for the -a option is to auto-detect the format of the
94           disk image.  Using this forces the disk format for -a options which
95           follow on the command line.  Using --format with no argument
96           switches back to auto-detection for subsequent -a options.
97
98           For example:
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100            virt-format --format=raw -a disk.img
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102           forces raw format (no auto-detection) for disk.img.
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104            virt-format --format=raw -a disk.img --format -a another.img
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106           forces raw format (no auto-detection) for disk.img and reverts to
107           auto-detection for another.img.
108
109           If you have untrusted raw-format guest disk images, you should use
110           this option to specify the disk format.  This avoids a possible
111           security problem with malicious guests (CVE-2010-3851).
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113       --label=LABEL
114           Set the filesystem label.
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116       --lvm=/dev/VG/LV
117           Create a Linux LVM2 logical volume called /dev/VG/LV.  You can
118           change the name of the volume group and logical volume.
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120       --lvm
121           Create a Linux LVM2 logical volume with the default name
122           (/dev/VG/LV).
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124       --lvm=none
125           Create no logical volume.  This is the default.
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127       --partition
128           Create either an MBR or GPT partition covering the whole disk.  MBR
129           is chosen if the disk size is < 2 TB, GPT if ≥ 2 TB.
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131           This is the default.
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133       --partition=gpt
134           Create a GPT partition.
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136       --partition=mbr
137           Create an MBR partition.
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139       --partition=none
140           Create no partition table.  Note that Windows may not be able to
141           see these disks.
142
143       -v
144       --verbose
145           Enable verbose messages for debugging.
146
147       -V
148       --version
149           Display version number and exit.
150
151       --wipe
152           Normally virt-format does not wipe data from the disk (because that
153           takes a long time).  Thus if there is data on the disk, it is only
154           hidden and partially overwritten by virt-format, and it might be
155           recovered by disk editing tools.
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157           If you use this option, virt-format writes zeroes over the whole
158           disk so that previous data is not recoverable.
159
160       -x  Enable tracing of libguestfs API calls.
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EXIT STATUS

163       This program returns 0 on success, or 1 on failure.
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AUTHOR

170       Richard W.M. Jones http://people.redhat.com/~rjones/
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COPYRIGHT

173       Copyright (C) 2012 Red Hat Inc.
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LICENSE

176       This program is free software; you can redistribute it and/or modify it
177       under the terms of the GNU General Public License as published by the
178       Free Software Foundation; either version 2 of the License, or (at your
179       option) any later version.
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181       This program is distributed in the hope that it will be useful, but
182       WITHOUT ANY WARRANTY; without even the implied warranty of
183       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
184       General Public License for more details.
185
186       You should have received a copy of the GNU General Public License along
187       with this program; if not, write to the Free Software Foundation, Inc.,
188       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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BUGS

191       To get a list of bugs against libguestfs, use this link:
192       https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
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194       To report a new bug against libguestfs, use this link:
195       https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
196
197       When reporting a bug, please supply:
198
199       •   The version of libguestfs.
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201       •   Where you got libguestfs (eg. which Linux distro, compiled from
202           source, etc)
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204       •   Describe the bug accurately and give a way to reproduce it.
205
206       •   Run libguestfs-test-tool(1) and paste the complete, unedited output
207           into the bug report.
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211guestfs-tools-1.46.1              2021-05-13                    virt-format(1)