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 Write out the results in CSV format (comma-separated values). This
91 format can be imported easily into databases and spreadsheets, but
92 read L</NOTE ABOUT CSV FORMAT> below.
96 =item B<--domain> guest
98 Add all the disks from the named libvirt guest. Domain UUIDs can be
99 used instead of names.
101 =item B<--format=raw|qcow2|..>
105 The default for the I<-a> option is to auto-detect the format of the
106 disk image. Using this forces the disk format for I<-a> options which
107 follow on the command line. Using I<--format> with no argument
108 switches back to auto-detection for subsequent I<-a> options.
112 virt-df --format=raw -a disk.img
114 forces raw format (no auto-detection) for C<disk.img>.
116 virt-df --format=raw -a disk.img --format -a another.img
118 forces raw format (no auto-detection) for C<disk.img> and reverts to
119 auto-detection for C<another.img>.
121 If you have untrusted raw-format guest disk images, you should use
122 this option to specify the disk format. This avoids a possible
123 security problem with malicious guests (CVE-2010-3851).
127 =item B<--human-readable>
129 Print sizes in human-readable format.
131 You are not allowed to use I<-h> and I<--csv> at the same time.
137 Print inodes instead of blocks.
139 =item B<--one-per-guest>
141 Run one libguestfs appliance per guest. Normally C<virt-df> will
142 add the disks from several guests to a single libguestfs appliance.
144 You might use this option in the following circumstances:
150 If you think an untrusted guest might actively try to exploit the
151 libguestfs appliance kernel, then this prevents one guest from
152 interfering with the stats printed for another guest.
156 If the kernel has a bug which stops it from accessing a
157 filesystem in one guest (see for example RHBZ#635373) then
158 this allows libguestfs to continue and report stats for further
165 Print UUIDs instead of names. This is useful for following
166 a guest even when the guest is migrated or renamed, or when
167 two guests happen to have the same name.
169 Note that only domains that we fetch from libvirt come with UUIDs.
170 For disk images, we still print the disk image name even when
171 this option is specified.
177 Enable verbose messages for debugging.
183 Display version number and exit.
187 Enable tracing of libguestfs API calls.
191 =head1 STATVFS NUMBERS
193 C<virt-df> (and L<df(1)>) get information by issuing a L<statvfs(3)>
194 system call. You can get the same information directly, either from
195 the host (using libguestfs) or inside the guest:
203 guestfish --ro -d GuestName -i statvfs /
205 (change C</> to see stats for other filesystems).
207 =item From inside the guest
211 python -c 'import os; s = os.statvfs ("/"); print s'
213 (change C</> to see stats for other filesystems).
217 =head1 NOTE ABOUT CSV FORMAT
219 Comma-separated values (CSV) is a deceptive format. It I<seems> like
220 it should be easy to parse, but it is definitely not easy to parse.
222 Myth: Just split fields at commas. Reality: This does I<not> work
223 reliably. This example has two columns:
227 Myth: Read the file one line at a time. Reality: This does I<not>
228 work reliably. This example has one row:
233 For shell scripts, use C<csvtool> (L<http://merjis.com/developers/csv>
234 also packaged in major Linux distributions).
236 For other languages, use a CSV processing library (eg. C<Text::CSV>
237 for Perl or Python's built-in csv library).
239 Most spreadsheets and databases can import CSV directly.
243 Libvirt guest names can contain arbitrary characters, some of which
244 have meaning to the shell such as C<#> and space. You may need to
245 quote or escape these characters on the command line. See the shell
246 manual page L<sh(1)> for details.
250 This program returns 0 if successful, or non-zero if there was an
258 L<virt-filesystems(1)>,
259 L<http://libguestfs.org/>.
263 Richard W.M. Jones L<http://people.redhat.com/~rjones/>
267 Copyright (C) 2009-2011 Red Hat Inc.
269 This program is free software; you can redistribute it and/or modify
270 it under the terms of the GNU General Public License as published by
271 the Free Software Foundation; either version 2 of the License, or
272 (at your option) any later version.
274 This program is distributed in the hope that it will be useful,
275 but WITHOUT ANY WARRANTY; without even the implied warranty of
276 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
277 GNU General Public License for more details.
279 You should have received a copy of the GNU General Public License
280 along with this program; if not, write to the Free Software
281 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.