Provided by: libguestfs-tools_1.24.5-1ubuntu0.1_amd64 
NAME
virt-make-fs - Make a filesystem from a tar archive or files
SYNOPSIS
virt-make-fs [--options] input.tar output.img
virt-make-fs [--options] input.tar.gz output.img
virt-make-fs [--options] directory output.img
DESCRIPTION
Virt-make-fs is a command line tool for creating a filesystem from a tar archive or some files in a
directory. It is similar to tools like mkisofs(1), genisoimage(1) and mksquashfs(1). Unlike those
tools, it can create common filesystem types like ext2/3 or NTFS, which can be useful if you want to
attach these filesystems to existing virtual machines (eg. to import large amounts of read-only data to a
VM).
To create blank disks, use virt-format(1). To create complex layouts, use guestfish(1).
Basic usage is:
virt-make-fs input output.img
where "input" is either a directory containing files that you want to add, or a tar archive (either
uncompressed tar or gzip-compressed tar); and "output.img" is a disk image. The input type is detected
automatically. The output disk image defaults to a raw ext2 sparse image unless you specify extra flags
(see "OPTIONS" below).
FILESYSTEM TYPE
The default filesystem type is "ext2". Just about any filesystem type that libguestfs supports can be
used (but not read-only formats like ISO9660). Here are some of the more common choices:
ext3
Note that ext3 filesystems contain a journal, typically 1-32 MB in size. If you are not going to use
the filesystem in a way that requires the journal, then this is just wasted overhead.
ntfs or vfat
Useful if exporting data to a Windows guest.
minix
Lower overhead than "ext2", but certain limitations on filename length and total filesystem size.
EXAMPLE
virt-make-fs --type=minix input minixfs.img
TO PARTITION OR NOT TO PARTITION
Optionally virt-make-fs can add a partition table to the output disk.
Adding a partition can make the disk image more compatible with certain virtualized operating systems
which don't expect to see a filesystem directly located on a block device (Linux doesn't care and will
happily handle both types).
On the other hand, if you have a partition table then the output image is no longer a straight
filesystem. For example you cannot run fsck(8) directly on a partitioned disk image. (However
libguestfs tools such as guestfish(1) and virt-resize(1) can still be used).
EXAMPLE
Add an MBR partition:
virt-make-fs --partition -- input disk.img
If the output disk image could be terabyte-sized or larger, it's better to use an EFI/GPT-compatible
partition table:
virt-make-fs --partition=gpt --size=+4T --format=qcow2 input disk.img
EXTRA SPACE
Unlike formats such as tar and squashfs, a filesystem does not "just fit" the files that it contains, but
might have extra space. Depending on how you are going to use the output, you might think this extra
space is wasted and want to minimize it, or you might want to leave space so that more files can be added
later. Virt-make-fs defaults to minimizing the extra space, but you can use the --size flag to leave
space in the filesystem if you want it.
An alternative way to leave extra space but not make the output image any bigger is to use an alternative
disk image format (instead of the default "raw" format). Using --format=qcow2 will use the native
QEmu/KVM qcow2 image format (check your hypervisor supports this before using it). This allows you to
choose a large --size but the extra space won't actually be allocated in the image until you try to store
something in it.
Don't forget that you can also use local commands including resize2fs(8) and virt-resize(1) to resize
existing filesystems, or rerun virt-make-fs to build another image from scratch.
EXAMPLE
virt-make-fs --format=qcow2 --size=+200M input output.img
OPTIONS
--help
Display brief help.
--version
Display version number and exit.
--debug
Enable debugging information.
--floppy
Create a virtual floppy disk.
Currently this preselects the size (1440K), partition type (MBR) and filesystem type (VFAT). In
future it may also choose the geometry.
--size=<N>
--size=+<N>
-s <N>
-s +<N>
Use the --size (or -s) option to choose the size of the output image.
If this option is not given, then the output image will be just large enough to contain all the
files, with not much wasted space.
To choose a fixed size output disk, specify an absolute number followed by b/K/M/G/T/P/E to mean
bytes, Kilobytes, Megabytes, Gigabytes, Terabytes, Petabytes or Exabytes. This must be large enough
to contain all the input files, else you will get an error.
To leave extra space, specify "+" (plus sign) and a number followed by b/K/M/G/T/P/E to mean bytes,
Kilobytes, Megabytes, Gigabytes, Terabytes, Petabytes or Exabytes. For example: --size=+200M means
enough space for the input files, and (approximately) an extra 200 MB free space.
Note that virt-make-fs estimates free space, and therefore will not produce filesystems containing
precisely the free space requested. (It is much more expensive and time-consuming to produce a
filesystem which has precisely the desired free space).
--format=<fmt>
-F <fmt>
Choose the output disk image format.
The default is "raw" (raw sparse disk image).
For other choices, see the qemu-img(1) manpage. The only other choice that would really make sense
here is "qcow2".
--type=<fs>
-t <fs>
Choose the output filesystem type.
The default is "ext2".
Any filesystem which is supported read-write by libguestfs can be used here.
--label=<LABEL>
Set the filesystem label.
--partition
--partition=<parttype>
If specified, this flag adds an MBR partition table to the output disk image.
You can change the partition table type, eg. --partition=gpt for large disks.
Note that if you just use a lonesome --partition, the Perl option parser might consider the next
parameter to be the partition type. For example:
virt-make-fs --partition input.tar output.img
would cause virt-make-fs to think you wanted to use a partition type of "input.tar" which is
completely wrong. To avoid this, use -- (a double dash) between options and the input and output
arguments:
virt-make-fs --partition -- input.tar output.img
For MBR, virt-make-fs sets the partition type byte automatically.
SHELL QUOTING
Libvirt guest names can contain arbitrary characters, some of which have meaning to the shell such as "#"
and space. You may need to quote or escape these characters on the command line. See the shell manual
page sh(1) for details.
SEE ALSO
guestfish(1), virt-format(1), virt-resize(1), virt-tar-in(1), mkisofs(1), genisoimage(1), mksquashfs(1),
mke2fs(8), resize2fs(8), guestfs(3), Sys::Guestfs(3), http://libguestfs.org/.
AUTHOR
Richard W.M. Jones http://people.redhat.com/~rjones/
COPYRIGHT
Copyright (C) 2010-2012 Red Hat Inc.
LICENSE
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.
BUGS
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.