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New tool: virt-format: erase and make blank disks.

Browse Source 
This tool allows you to easily reformat a disk, creating a blank disk
with optional partition, LVM and empty filesystem.
This commit is contained in:
Richard W.M. Jones
2012-01-17 17:34:24 +00:00
parent dd0707be5f
commit 6de1a1242e
10 changed files with 758 additions and 1 deletions
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4
.gitignore vendored
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@@ -105,6 +105,9 @@ fish/virt-copy-in.1
fish/virt-copy-out.1
fish/virt-tar-in.1
fish/virt-tar-out.1
format/stamp-virt-format.pod
format/virt-format
format/virt-format.1
fuse/guestmount
fuse/guestmount.1
fuse/stamp-guestmount.pod
@@ -145,6 +148,7 @@ html/virt-copy-out.1.html
html/virt-df.1.html
html/virt-edit.1.html
html/virt-filesystems.1.html
html/virt-format.1.html
html/virt-inspector.1.html
html/virt-list-filesystems.1.html
html/virt-list-partitions.1.html

3
Makefile.am
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@@ -52,7 +52,7 @@ SUBDIRS += test-tool
SUBDIRS += fish
# virt-tools in C.
SUBDIRS += align cat df edit inspector rescue
SUBDIRS += align cat df edit format inspector rescue
# Language bindings.
if HAVE_PERL
@@ -187,6 +187,7 @@ HTMLFILES = \
html/virt-df.1.html \
html/virt-edit.1.html \
html/virt-filesystems.1.html \
html/virt-format.1.html \
html/virt-inspector.1.html \
html/virt-list-filesystems.1.html \
html/virt-list-partitions.1.html \

1
configure.ac
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@@ -1018,6 +1018,7 @@ AC_CONFIG_FILES([Makefile
erlang/examples/Makefile
examples/Makefile
fish/Makefile
format/Makefile
fuse/Makefile
generator/Makefile
gnulib/lib/Makefile

78
format/Makefile.am Normal file
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@@ -0,0 +1,78 @@
# libguestfs virt format tool
# Copyright (C) 2012 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.
include $(top_srcdir)/subdir-rules.mk
EXTRA_DIST = \
virt-format.pod
CLEANFILES = stamp-virt-format.pod
bin_PROGRAMS = virt-format
SHARED_SOURCE_FILES = \
../fish/config.c \
../fish/inspect.c \
../fish/keys.c \
../fish/options.h \
../fish/options.c \
../fish/virt.c
virt_format_SOURCES = \
$(SHARED_SOURCE_FILES) \
format.c
virt_format_CFLAGS = \
-DGUESTFS_WARN_DEPRECATED=1 \
-I$(top_srcdir)/src -I$(top_builddir)/src \
-I$(top_srcdir)/fish \
-I$(srcdir)/../gnulib/lib -I../gnulib/lib \
-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
$(WARN_CFLAGS) $(WERROR_CFLAGS) \
$(LIBCONFIG_CFLAGS) \
$(LIBVIRT_CFLAGS)
virt_format_LDADD = \
$(LIBCONFIG_LIBS) \
$(top_builddir)/src/libguestfs.la \
../gnulib/lib/libgnu.la \
$(LIBVIRT_LIBS)
# Manual pages and HTML files for the website.
man_MANS = virt-format.1
noinst_DATA = $(top_builddir)/html/virt-format.1.html
virt-format.1 $(top_builddir)/html/virt-format.1.html: stamp-virt-format.pod
stamp-virt-format.pod: virt-format.pod
$(top_builddir)/podwrapper.sh \
--man virt-format.1 \
--html $(top_builddir)/html/virt-format.1.html \
$<
touch $@
# Tests.
# random_val := $(shell awk 'BEGIN{srand(); print 1+int(255*rand())}' < /dev/null)
# TESTS_ENVIRONMENT = \
# MALLOC_PERTURB_=$(random_val) \
# LD_LIBRARY_PATH=$(top_builddir)/src/.libs \
# LIBGUESTFS_PATH=$(top_builddir)/appliance \
# TMPDIR=$(top_builddir)
# TESTS = test-virt-format.sh

456
format/format.c Normal file
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@@ -0,0 +1,456 @@
/* virt-format
* Copyright (C) 2012 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.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <inttypes.h>
#include <unistd.h>
#include <getopt.h>
#include <locale.h>
#include <assert.h>
#include <libintl.h>
#include "progname.h"
#include "c-ctype.h"
#include "guestfs.h"
#include "options.h"
/* These globals are shared with options.c. */
guestfs_h *g;
int read_only = 0;
int live = 0;
int verbose = 0;
int keys_from_stdin = 0;
int echo_keys = 0;
int inspector = 0;
const char *libvirt_uri = NULL;
static const char *filesystem = NULL;
static const char *vg = NULL, *lv = NULL;
static const char *partition = "DEFAULT";
static int wipe = 0;
static void parse_vg_lv (const char *lvm);
static int do_format (void);
static int do_rescan (char **devices);
static inline char *
bad_cast (char const *s)
{
return (char *) s;
}
static void __attribute__((noreturn))
usage (int status)
{
char *warning =
_("IMPORTANT NOTE: This program ERASES ALL DATA on disks.");
if (status != EXIT_SUCCESS)
fprintf (stderr, _("Try `%s --help' for more information.\n%s\n"),
program_name, warning);
else {
fprintf (stdout,
_("%s: erase and make a blank disk\n"
"Copyright (C) 2012 Red Hat Inc.\n"
"\n"
"%s\n"
"\n"
"Usage:\n"
" %s [--options] -a disk.img [-a disk.img ...]\n"
"Options:\n"
" -a|--add image Add image\n"
" --filesystem=.. Create empty filesystem\n"
" --format[=raw|..] Force disk format for -a option\n"
" --help Display brief help\n"
" --lvm=.. Create Linux LVM2 logical volume\n"
" --partition=.. Create / set partition type\n"
" -v|--verbose Verbose messages\n"
" -V|--version Display version and exit\n"
" --wipe Write zeroes over whole disk\n"
" -x Trace libguestfs API calls\n"
"For more information, see the manpage %s(1).\n"
"\n"
"%s\n\n"),
program_name, warning, program_name, program_name,
warning);
}
exit (status);
}
int
main (int argc, char *argv[])
{
/* Set global program name that is not polluted with libtool artifacts. */
set_program_name (argv[0]);
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEBASEDIR);
textdomain (PACKAGE);
enum { HELP_OPTION = CHAR_MAX + 1 };
static const char *options = "a:c:d:qvVx";
static const struct option long_options[] = {
{ "add", 1, 0, 'a' },
{ "filesystem", 1, 0, 0 },
{ "format", 2, 0, 0 },
{ "help", 0, 0, HELP_OPTION },
{ "lvm", 2, 0, 0 },
{ "partition", 2, 0, 0 },
{ "verbose", 0, 0, 'v' },
{ "version", 0, 0, 'V' },
{ "wipe", 0, 0, 0 },
{ 0, 0, 0, 0 }
};
struct drv *drvs = NULL;
struct drv *drv;
const char *format = NULL;
int c;
int option_index;
int retry, retries;
g = guestfs_create ();
if (g == NULL) {
fprintf (stderr, _("guestfs_create: failed to create handle\n"));
exit (EXIT_FAILURE);
}
argv[0] = bad_cast (program_name);
for (;;) {
c = getopt_long (argc, argv, options, long_options, &option_index);
if (c == -1) break;
switch (c) {
case 0: /* options which are long only */
if (STREQ (long_options[option_index].name, "format")) {
if (!optarg || STREQ (optarg, ""))
format = NULL;
else
format = optarg;
} else if (STREQ (long_options[option_index].name, "filesystem")) {
if (STREQ (optarg, "none"))
filesystem = NULL;
else if (optarg[0] == '-') { /* eg: --filesystem --lvm */
fprintf (stderr, _("%s: no filesystem was specified\n"),
program_name);
exit (EXIT_FAILURE);
} else
filesystem = optarg;
} else if (STREQ (long_options[option_index].name, "lvm")) {
if (vg || lv) {
fprintf (stderr,
_("%s: --lvm option cannot be given multiple times\n"),
program_name);
exit (EXIT_FAILURE);
}
if (optarg == NULL) {
vg = strdup ("VG");
lv = strdup ("LV");
if (!vg || !lv) { perror ("strdup"); exit (EXIT_FAILURE); }
}
else if (STREQ (optarg, "none"))
vg = lv = NULL;
else
parse_vg_lv (optarg);
} else if (STREQ (long_options[option_index].name, "partition")) {
if (optarg == NULL)
partition = "DEFAULT";
else if (STREQ (optarg, "none"))
partition = NULL;
else
partition = optarg;
} else if (STREQ (long_options[option_index].name, "wipe")) {
wipe = 1;
} else {
fprintf (stderr, _("%s: unknown long option: %s (%d)\n"),
program_name, long_options[option_index].name, option_index);
exit (EXIT_FAILURE);
}
break;
case 'a':
OPTION_a;
break;
case 'v':
OPTION_v;
break;
case 'V':
OPTION_V;
break;
case 'x':
OPTION_x;
break;
case HELP_OPTION:
usage (EXIT_SUCCESS);
default:
usage (EXIT_FAILURE);
}
}
/* These are really constants, but they have to be variables for the
* options parsing code. Assert here that they have known-good
* values.
*/
assert (read_only == 0);
assert (inspector == 0);
assert (live == 0);
/* Must be no extra arguments on the command line. */
if (optind != argc)
usage (EXIT_FAILURE);
/* The user didn't specify any drives to format. */
if (drvs == NULL)
usage (EXIT_FAILURE);
/* Because the libguestfs kernel can get stuck rereading the
* partition table after things have been erased, we sometimes need
* to completely restart the guest. Hence this complex retry logic.
*/
for (retries = 0; retries <= 1; ++retries) {
/* Add domains/drives from the command line (for a single guest). */
add_drives (drvs, 'a');
if (guestfs_launch (g) == -1)
exit (EXIT_FAILURE);
/* Perform the format. */
retry = do_format ();
if (!retry)
break;
if (retries == 0) {
/* We're going to silently retry, after reopening the connection. */
guestfs_h *g2;
g2 = guestfs_create ();
guestfs_set_verbose (g2, guestfs_get_verbose (g));
guestfs_set_trace (g2, guestfs_get_trace (g));
guestfs_close (g);
g = g2;
}
else {
/* Failed. */
fprintf (stderr,
_("%s: failed to rescan the disks after two attempts. This\n"
"may mean there is some sort of partition table or disk\n"
"data which we are unable to remove. If you think this\n"
"is a bug, please file a bug at http://libguestfs.org/\n"),
program_name);
exit (EXIT_FAILURE);
}
}
/* Free up data structures. */
free_drives (drvs);
guestfs_close (g);
exit (EXIT_SUCCESS);
}
/* Parse lvm string of the form "/dev/VG/LV" or "VG/LV".
* This sets the global variables 'vg' and 'lv', or exits on failure.
*/
static void
parse_vg_lv (const char *lvm)
{
size_t i;
if (STRPREFIX (lvm, "/dev/"))
lvm += 5;
i = strcspn (lvm, "/");
if (lvm[i]) {
vg = strndup (lvm, i);
lv = strdup (lvm + i + 1);
if (!vg || !lv) {
perror ("strdup");
exit (EXIT_FAILURE);
}
} else {
cannot_parse:
fprintf (stderr, _("%s: cannot parse --lvm option (%s)\n"),
program_name, lvm);
exit (EXIT_FAILURE);
}
if (strchr (vg, '/') || strchr (lv, '/'))
goto cannot_parse;
}
/* Returns 0 on success, 1 if we need to retry. */
static int
do_format (void)
{
char **devices;
size_t i, pass;
int ret;
devices = guestfs_list_devices (g);
if (devices == NULL)
exit (EXIT_FAILURE);
/* Erase the disks. */
if (!wipe) {
char **parts;
/* No wipe, but get rid of LVM metadata by erasing each partition. */
parts = guestfs_list_partitions (g);
if (parts == NULL)
exit (EXIT_FAILURE);
for (i = 0; parts[i] != NULL; ++i) {
if (guestfs_zero (g, parts[i]) == -1)
exit (EXIT_FAILURE);
free (parts[i]);
}
free (parts);
/* Then erase the partition table on each device. */
for (i = 0; devices[i] != NULL; ++i) {
if (guestfs_zero (g, devices[i]) == -1)
exit (EXIT_FAILURE);
}
}
else /* wipe */ {
for (i = 0; devices[i] != NULL; ++i) {
if (guestfs_zero_device (g, devices[i]) == -1)
exit (EXIT_FAILURE);
}
}
if (do_rescan (devices)) {
ret = 1; /* which means, reopen the handle and retry */
goto out;
}
/* Format each disk. */
for (i = 0; devices[i] != NULL; ++i) {
char *dev = devices[i];
int free_dev = 0;
if (partition) {
const char *ptype = partition;
int64_t dev_size;
/* If partition has the magic value "DEFAULT", choose either MBR or GPT.*/
if (STREQ (partition, "DEFAULT")) {
dev_size = guestfs_blockdev_getsize64 (g, devices[i]);
if (dev_size == -1)
exit (EXIT_FAILURE);
ptype = dev_size < INT64_C(2)*1024*1024*1024*1024 ? "mbr" : "gpt";
}
if (guestfs_part_disk (g, devices[i], ptype) == -1)
exit (EXIT_FAILURE);
if (asprintf (&dev, "%s1", devices[i]) == -1) {
perror ("asprintf");
exit (EXIT_FAILURE);
}
free_dev = 1;
}
if (vg && lv) {
char *devs[2] = { dev, NULL };
if (guestfs_pvcreate (g, dev) == -1)
exit (EXIT_FAILURE);
if (guestfs_vgcreate (g, vg, devs) == -1)
exit (EXIT_FAILURE);
if (guestfs_lvcreate (g, lv, vg, 32) == -1) /* 32 MB is smallest LV */
exit (EXIT_FAILURE);
if (free_dev)
free (dev);
if (asprintf (&dev, "/dev/%s/%s", vg, lv) == -1) {
perror ("asprintf");
exit (EXIT_FAILURE);
}
free_dev = 1;
if (guestfs_lvresize_free (g, dev, 100) == -1)
exit (EXIT_FAILURE);
}
if (filesystem) {
if (guestfs_mkfs_opts (g, filesystem, dev, -1) == -1)
exit (EXIT_FAILURE);
}
if (free_dev)
free (dev);
}
if (guestfs_sync (g) == -1)
exit (EXIT_FAILURE);
ret = 0;
out:
/* Free device list. */
for (i = 0; devices[i] != NULL; ++i)
free (devices[i]);
free (devices);
return ret;
}
/* Rescan everything so the kernel knows that there are no partition
* tables, VGs etc. Returns 0 on success, 1 if we need to retry.
*/
static int
do_rescan (char **devices)
{
size_t i;
int errors = 0;
guestfs_error_handler_cb old_error_cb;
void *old_error_data;
old_error_cb = guestfs_get_error_handler (g, &old_error_data);
guestfs_set_error_handler (g, NULL, NULL);
for (i = 0; devices[i] != NULL; ++i) {
if (guestfs_blockdev_rereadpt (g, devices[i]) == -1)
errors++;
}
if (guestfs_vgscan (g) == -1)
errors++;
guestfs_set_error_handler (g, old_error_cb, old_error_data);
return errors ? 1 : 0;
}

207
format/virt-format.pod Executable file
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@@ -0,0 +1,207 @@
=encoding utf8
=head1 NAME
virt-format - Erase and make a blank disk
=head1 SYNOPSIS
virt-format [--options] -a disk.img [-a disk.img ...]
=head1 DESCRIPTION
Virt-format takes an existing disk file (or it can be a host
partition, LV etc), B<erases all data on it>, and formats it as a
blank disk. It can optionally create partition tables, empty
filesystems, logical volumes and more.
To create a disk containing data, you may be better to use
L<virt-make-fs(1)>. If you are creating a blank disk to use in
L<guestfish(1)>, you should instead use the guestfish I<-N> option.
Normal usage would be something like this:
virt-format -a disk.qcow
or this:
virt-format -a /dev/VG/LV
C<disk.qcow> or C</dev/VG/LV> must exist already. B<Any data on these
disks will be erased by these commands>. These commands will create a
single empty partition covering the whole disk, with no filesystem
inside it.
Additional parameters can be used to control the creation of
partitions, filesystems, etc. The most commonly used options are:
=over 4
=item I<--filesystem=[ext3|ntfs|vfat|...]>
Create an empty filesystem (C<ext3>, C<ntfs> etc) inside the partition.
=item I<--lvm[=/dev/VG/LV]>
Create a Linux LVM2 logical volume on the disk. When used with
I<--filesystem>, the filesystem is created inside the LV.
=back
For more information about these and other options, see
L</OPTIONS> below.
The format of the disk is normally auto-detected, but you can also
force it by using the I<--format> option (q.v.). In situations where
you do not trust the existing content of the disk, then it is
advisable to use this option to avoid possible exploits.
=head1 OPTIONS
=over 4
=item B<--help>
Display brief help.
=item B<-a> file
=item B<--add> file
Add I<file>, a disk image, host partition, LV, external USB disk, etc.
The format of the disk image is auto-detected. To override this and
force a particular format use the I<--format=..> option.
B<Any existing data on the disk is erased.>
=item B<--filesystem=ext3|ntfs|vfat|...>
Create an empty filesystem of the specified type. Many filesystem
types are supported by libguestfs.
=item B<--filesystem=none>
Create no filesystem. This is the default.
=item B<--format=raw|qcow2|..>
=item B<--format>
The default for the I<-a> option is to auto-detect the format of the
disk image. Using this forces the disk format for I<-a> options which
follow on the command line. Using I<--format> with no argument
switches back to auto-detection for subsequent I<-a> options.
For example:
virt-format --format=raw -a disk.img
forces raw format (no auto-detection) for C<disk.img>.
virt-format --format=raw -a disk.img --format -a another.img
forces raw format (no auto-detection) for C<disk.img> and reverts to
auto-detection for C<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).
=item B<--lvm=/dev/I<VG>/I<LV>>
Create a Linux LVM2 logical volume called C</dev/I<VG>/I<LV>>. You
can change the name of the volume group and logical volume.
=item B<--lvm>
Create a Linux LVM2 logical volume with the default name
(C</dev/VG/LV>).
=item B<--lvm=none>
Create no logical volume. This is the default.
=item B<--partition>
Create either an MBR or GPT partition covering the whole disk. MBR is
chosen if the disk size is E<lt> 2 TB, GPT if E<ge> 2 TB.
This is the default.
=item B<--partition=gpt>
Create a GPT partition.
=item B<--partition=mbr>
Create an MBR partition.
=item B<--partition=none>
Create no partition table. Note that Windows may not be able to see
these disks.
=item B<-v>
=item B<--verbose>
Enable verbose messages for debugging.
=item B<-V>
=item B<--version>
Display version number and exit.
=item B<--wipe>
Normally virt-format does not wipe data from the disk (because that
takes a long time). Thus if there is data on the disk, it is only
hidden and partially overwritten by virt-format, and it might be
recovered by disk editing tools.
If you use this option, virt-format writes zeroes over the whole disk
so that previous data is not recoverable.
=item B<-x>
Enable tracing of libguestfs API calls.
=back
=head1 EXIT STATUS
This program returns C<0> on success, or C<1> on failure.
=head1 SEE ALSO
L<guestfs(3)>,
L<guestfish(1)>,
L<virt-filesystems(1)>,
L<virt-make-fs(1)>,
L<virt-rescue(1)>,
L<virt-resize(1)>,
L<http://libguestfs.org/>.
=head1 AUTHOR
Richard W.M. Jones L<http://people.redhat.com/~rjones/>
=head1 COPYRIGHT
Copyright (C) 2012 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.

1
po/POTFILES.in
View File

@@ -124,6 +124,7 @@ fish/supported.c
fish/tilde.c
fish/time.c
fish/virt.c
format/format.c
fuse/dircache.c
fuse/guestmount.c
inspector/virt-inspector.c

5
src/guestfs.pod
View File

@@ -2955,6 +2955,10 @@ L<guestfish(1)>, the command-line shell, and various shell scripts
built on top such as L<virt-copy-in(1)>, L<virt-copy-out(1)>,
L<virt-tar-in(1)>, L<virt-tar-out(1)>.
=item C<format>
L<virt-format(1)> command and documentation.
=item C<fuse>
L<guestmount(1)>, FUSE (userspace filesystem) built on top of libguestfs.
@@ -3271,6 +3275,7 @@ L<virt-copy-out(1)>,
L<virt-df(1)>,
L<virt-edit(1)>,
L<virt-filesystems(1)>,
L<virt-format(1)>,
L<virt-inspector(1)>,
L<virt-list-filesystems(1)>,
L<virt-list-partitions(1)>,

1
tests/extra/Makefile.am
View File

@@ -102,6 +102,7 @@ test-prerequisites:
test-tools-null:
$(RUN_VG) ../../fish/guestfish -N part exit
$(RUN_VG) ../../align/virt-alignment-scan -a test1.img >/dev/null
$(RUN_VG) ../../format/virt-format -a test1.img >/dev/null
rm test1.img
$(RUN_VG) ../../cat/virt-filesystems -a /dev/null >/dev/null
$(RUN_VG) ../../cat/virt-filesystems -a /dev/null --all --long -h --uuid >/dev/null

3
tools/virt-make-fs
View File

@@ -54,6 +54,8 @@ 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 L<virt-format(1)>.
Basic usage is:
virt-make-fs input output.img
@@ -557,6 +559,7 @@ manual page L<sh(1)> for details.
=head1 SEE ALSO
L<guestfish(1)>,
L<virt-format(1)>,
L<virt-resize(1)>,
L<virt-tar-in(1)>,
L<mkisofs(1)>,