5 virt-df - Display free space on virtual filesystems
11 virt-df [--options] -d domname
13 virt-df [--options] -a disk.img [-a disk.img ...]
17 virt-df [--options] domname
19 virt-df [--options] disk.img [disk.img ...]
23 C<virt-df> is a command line tool to display free space on virtual
24 machine filesystems. Unlike other tools, it doesn't just display the
25 size of disk allocated to a virtual machine, but can look inside disk
26 images to see how much space is really being used.
28 If used without any I<-a> or I<-d> arguments, C<virt-df> checks with
29 libvirt to get a list of all active and inactive guests, and performs
30 a C<df>-type operation on each one in turn, printing out the results.
32 If any I<-a> or I<-d> arguments are specified, C<virt-df> performs a
33 C<df>-type operation on either the single named libvirt domain, or on
34 the disk image(s) listed on the command line (which must all belong to
35 a single VM). In this mode (with arguments), C<virt-df> will I<only
36 work for a single guest>. If you want to run on multiple guests, then
37 you have to invoke C<virt-df> multiple times.
39 Use the I<--csv> option to get a format which can be easily parsed by
40 other programs. Other options are similar to the standard L<df(1)>
45 Show disk usage for a single libvirt guest called C<F14x64>. Make the
46 output human-readable:
48 # virt-df -d F14x64 -h
49 Filesystem Size Used Available Use%
50 F14x64:/dev/sda1 484M 66M 393M 14%
51 F14x64:/dev/vg_f13x64/lv_root 7.4G 3.4G 4.0G 46%
53 Show disk usage for a disk image file called C<test.img>:
55 $ virt-df -a test1.img
56 Filesystem 1K-blocks Used Available Use%
57 test1.img:/dev/sda1 99099 1551 92432 2%
71 Add I<file> which should be a disk image from a virtual machine. If
72 the virtual machine has multiple block devices, you must supply all of
73 them with separate I<-a> options.
75 The format of the disk image is auto-detected. To override this and
76 force a particular format use the I<--format=..> option.
80 =item B<--connect> URI
82 If using libvirt, connect to the given I<URI>. If omitted, then we
83 connect to the default libvirt hypervisor.
85 If you specify guest block devices directly (I<-a>), then libvirt is
90 =item B<--domain> guest
92 Add all the disks from the named libvirt guest. Domain UUIDs can be
93 used instead of names.
95 =item B<--format=raw|qcow2|..>
99 The default for the I<-a> option is to auto-detect the format of the
100 disk image. Using this forces the disk format for I<-a> options which
101 follow on the command line. Using I<--format> with no argument
102 switches back to auto-detection for subsequent I<-a> options.
106 virt-df --format=raw -a disk.img
108 forces raw format (no auto-detection) for C<disk.img>.
110 virt-df --format=raw -a disk.img --format -a another.img
112 forces raw format (no auto-detection) for C<disk.img> and reverts to
113 auto-detection for C<another.img>.
115 If you have untrusted raw-format guest disk images, you should use
116 this option to specify the disk format. This avoids a possible
117 security problem with malicious guests (CVE-2010-3851).
121 =item B<--human-readable>
123 Print sizes in human-readable format.
125 You are not allowed to use I<-h> and I<--csv> at the same time.
127 =item B<--inodes> | B<-i>
129 Print inodes instead of blocks.
131 =item B<--one-per-guest>
133 Run one libguestfs appliance per guest. Normally C<virt-df> will
134 add the disks from several guests to a single libguestfs appliance.
136 You might use this option in the following circumstances:
142 If you think an untrusted guest might actively try to exploit the
143 libguestfs appliance kernel, then this prevents one guest from
144 interfering with the stats printed for another guest.
148 If the kernel has a bug which stops it from accessing a
149 filesystem in one guest (see for example RHBZ#635373) then
150 this allows libguestfs to continue and report stats for further
157 Print UUIDs instead of names. This is useful for following
158 a guest even when the guest is migrated or renamed, or when
159 two guests happen to have the same name.
161 Note that only domains that we fetch from libvirt come with UUIDs.
162 For disk images, we still print the disk image name even when
163 this option is specified.
169 Enable verbose messages for debugging.
175 Display version number and exit.
179 Enable tracing of libguestfs API calls.
183 =head1 NOTE ABOUT CSV FORMAT
185 Comma-separated values (CSV) is a deceptive format. It I<seems> like
186 it should be easy to parse, but it is definitely not easy to parse.
188 Myth: Just split fields at commas. Reality: This does I<not> work
189 reliably. This example has two columns:
193 Myth: Read the file one line at a time. Reality: This does I<not>
194 work reliably. This example has one row:
199 For shell scripts, use C<csvtool> (L<http://merjis.com/developers/csv>
200 also packaged in major Linux distributions).
202 For other languages, use a CSV processing library (eg. C<Text::CSV>
203 for Perl or Python's built-in csv library).
205 Most spreadsheets and databases can import CSV directly.
209 Libvirt guest names can contain arbitrary characters, some of which
210 have meaning to the shell such as C<#> and space. You may need to
211 quote or escape these characters on the command line. See the shell
212 manual page L<sh(1)> for details.
219 L<virt-filesystems(1)>,
220 L<http://libguestfs.org/>.
224 Richard W.M. Jones L<http://people.redhat.com/~rjones/>
228 Copyright (C) 2009-2011 Red Hat Inc.
230 This program is free software; you can redistribute it and/or modify
231 it under the terms of the GNU General Public License as published by
232 the Free Software Foundation; either version 2 of the License, or
233 (at your option) any later version.
235 This program is distributed in the hope that it will be useful,
236 but WITHOUT ANY WARRANTY; without even the implied warranty of
237 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
238 GNU General Public License for more details.
240 You should have received a copy of the GNU General Public License
241 along with this program; if not, write to the Free Software
242 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.