virt-df - Display free space on virtual filesystems
virt-df [--options] -d domname virt-df [--options] -a disk.img [-a disk.img ...]
virt-df [--options] domname virt-df [--options] disk.img [disk.img ...]
"virt-df" is a command line tool to display free space on virtual machine filesystems. Unlike other tools, it doesn't just display the size of disk allocated to a virtual machine, but can look inside disk images to see how much space is really being used.
If used without any -a or -d arguments, "virt-df" checks with libvirt to get a list of all active and inactive guests, and performs a "df"-type operation on each one in turn, printing out the results.
If any -a or -d arguments are specified, "virt-df" performs a "df"-type operation on either the single named libvirt domain, or on the disk image(s) listed on the command line (which must all belong to a single VM). In this mode (with arguments), "virt-df" will only work for a single guest. If you want to run on multiple guests, then you have to invoke "virt-df" multiple times.
Use the --csv option to get a format which can be easily parsed by other programs. Other options are similar to the standard df(1) command.
Show disk usage for a single libvirt guest called "F14x64". Make the output human-readable:
# virt-df -d F14x64 -h Filesystem Size Used Available Use% F14x64:/dev/sda1 484M 66M 393M 14% F14x64:/dev/vg_f13x64/lv_root 7.4G 3.4G 4.0G 46%
Show disk usage for a disk image file called test.img:
$ virt-df -a test1.img Filesystem 1K-blocks Used Available Use% test1.img:/dev/sda1 99099 1551 92432 2%
If a single guest has multiple disks, use the -a option repeatedly. A plus sign ("+") is displayed for each additional disk. Note: Do not do this with unrelated guest disks.
$ virt-df -a Win7x32TwoDisks-a -a Win7x32TwoDisks-b Filesystem 1K-blocks Used Available Use% Win7x32TwoDisks-a+:/dev/sda1 102396 24712 77684 25% Win7x32TwoDisks-a+:/dev/sda2 12478460 7403416 5075044 60% Win7x32TwoDisks-a+:/dev/sdb1 521212 55728 465484 11%
- Display brief help.
- -a FILE
- --add FILE
- Add "FILE" which should be a disk image
from a virtual machine. If the virtual machine has multiple block devices,
you must supply all of them with separate -a options.
The format of the disk image is auto-detected. To override this and force a particular format use the --format=.. option.
- -a URI
- --add URI
- Add a remote disk. See "ADDING REMOTE STORAGE" in guestfish(1).
- This parameter sets the sector size of the disk image. It affects all explicitly added subsequent disks after this parameter. Using --blocksize with no argument switches the disk sector size to the default value which is usually 512 bytes. See also "guestfs_add_drive_opts" in guestfs(3).
- -c URI
- --connect URI
- If using libvirt, connect to the given URI. If omitted, then we
connect to the default libvirt hypervisor.
If you specify guest block devices directly (-a), then libvirt is not used at all.
- Write out the results in CSV format (comma-separated values). This format can be imported easily into databases and spreadsheets, but read "NOTE ABOUT CSV FORMAT" below.
- -d guest
- --domain guest
- Add all the disks from the named libvirt guest. Domain UUIDs can be used instead of names.
- The default for the -a option is to auto-detect the format of the
disk image. Using this forces the disk format for -a options which
follow on the command line. Using --format with no argument
switches back to auto-detection for subsequent -a options.
virt-df --format=raw -a disk.img
forces raw format (no auto-detection) for disk.img.
virt-df --format=raw -a disk.img --format -a another.img
forces raw format (no auto-detection) for disk.img and reverts to auto-detection for another.img.
If you have untrusted raw-format guest disk images, you should use this option to specify the disk format. This avoids a possible security problem with malicious guests (CVE-2010-3851).
- Print sizes in human-readable format.
You are not allowed to use -h and --csv at the same time.
- Print inodes instead of blocks.
- Since libguestfs 1.22, this is the default. This option does nothing and is left here for backwards compatibility with older scripts.
- -P nr_threads
- Since libguestfs 1.22, virt-df is multithreaded and examines guests in
parallel. By default the number of threads to use is chosen based on the
amount of free memory available at the time that virt-df is started. You
can force virt-df to use at most
"nr_threads" by using the -P
Note that -P 0 means to autodetect, and -P 1 means to use a single thread.
- Print UUIDs instead of names. This is useful for following a guest even
when the guest is migrated or renamed, or when two guests happen to have
the same name.
Note that only domains that we fetch from libvirt come with UUIDs. For disk images, we still print the disk image name even when this option is specified.
- Enable verbose messages for debugging.
- Display version number and exit.
- Enable tracing of libguestfs API calls.
NOTE ABOUT CSV FORMAT¶
Comma-separated values (CSV) is a deceptive format. It seems like it should be easy to parse, but it is definitely not easy to parse.
Myth: Just split fields at commas. Reality: This does not work reliably. This example has two columns:
Myth: Read the file one line at a time. Reality: This does not work reliably. This example has one row:
For shell scripts, use "csvtool" (https://github.com/Chris00/ocaml-csv also packaged in major Linux distributions).
For other languages, use a CSV processing library (eg. "Text::CSV" for Perl or Python’s built-in csv library).
Most spreadsheets and databases can import CSV directly.
This program returns 0 if successful, or non-zero if there was an error.
Richard W.M. Jones http://people.redhat.com/~rjones/
Copyright (C) 2009-2020 Red Hat Inc.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
To get a list of bugs against libguestfs, use this link: https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
To report a new bug against libguestfs, use this link: https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
When reporting a bug, please supply:
- The version of libguestfs.
- Where you got libguestfs (eg. which Linux distro, compiled from source, etc)
- Describe the bug accurately and give a way to reproduce it.
- Run libguestfs-test-tool(1) and paste the complete, unedited output into the bug report.