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.
94 =item B<--format=raw|qcow2|..>
98 The default for the I<-a> option is to auto-detect the format of the
99 disk image. Using this forces the disk format for I<-a> options which
100 follow on the command line. Using I<--format> with no argument
101 switches back to auto-detection for subsequent I<-a> options.
105 virt-df --format=raw -a disk.img
107 forces raw format (no auto-detection) for C<disk.img>.
109 virt-df --format=raw -a disk.img --format -a another.img
111 forces raw format (no auto-detection) for C<disk.img> and reverts to
112 auto-detection for C<another.img>.
114 If you have untrusted raw-format guest disk images, you should use
115 this option to specify the disk format. This avoids a possible
116 security problem with malicious guests (CVE-2010-3851).
120 =item B<--human-readable>
122 Print sizes in human-readable format.
124 You are not allowed to use I<-h> and I<--csv> at the same time.
126 =item B<--inodes> | B<-i>
128 Print inodes instead of blocks.
130 =item B<--one-per-guest>
132 Run one libguestfs appliance per guest. Normally C<virt-df> will
133 add the disks from several guests to a single libguestfs appliance.
135 You might use this option in the following circumstances:
141 If you think an untrusted guest might actively try to exploit the
142 libguestfs appliance kernel, then this prevents one guest from
143 interfering with the stats printed for another guest.
147 If the kernel has a bug which stops it from accessing a
148 filesystem in one guest (see for example RHBZ#635373) then
149 this allows libguestfs to continue and report stats for further
156 Print UUIDs instead of names. This is useful for following
157 a guest even when the guest is migrated or renamed, or when
158 two guests happen to have the same name.
160 Note that only domains that we fetch from libvirt come with UUIDs.
161 For disk images, we still print the disk image name even when
162 this option is specified.
168 Enable verbose messages for debugging.
174 Display version number and exit.
178 Enable tracing of libguestfs API calls.
182 =head1 NOTE ABOUT CSV FORMAT
184 Comma-separated values (CSV) is a deceptive format. It I<seems> like
185 it should be easy to parse, but it is definitely not easy to parse.
187 Myth: Just split fields at commas. Reality: This does I<not> work
188 reliably. This example has two columns:
192 Myth: Read the file one line at a time. Reality: This does I<not>
193 work reliably. This example has one row:
198 For shell scripts, use C<csvtool> (L<http://merjis.com/developers/csv>
199 also packaged in major Linux distributions).
201 For other languages, use a CSV processing library (eg. C<Text::CSV>
202 for Perl or Python's built-in csv library).
204 Most spreadsheets and databases can import CSV directly.
208 Libvirt guest names can contain arbitrary characters, some of which
209 have meaning to the shell such as C<#> and space. You may need to
210 quote or escape these characters on the command line. See the shell
211 manual page L<sh(1)> for details.
218 L<virt-filesystems(1)>,
219 L<http://libguestfs.org/>.
223 Richard W.M. Jones L<http://people.redhat.com/~rjones/>
227 Copyright (C) 2009-2011 Red Hat Inc.
229 This program is free software; you can redistribute it and/or modify
230 it under the terms of the GNU General Public License as published by
231 the Free Software Foundation; either version 2 of the License, or
232 (at your option) any later version.
234 This program is distributed in the hope that it will be useful,
235 but WITHOUT ANY WARRANTY; without even the implied warranty of
236 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
237 GNU General Public License for more details.
239 You should have received a copy of the GNU General Public License
240 along with this program; if not, write to the Free Software
241 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.