Rather than me explaining over again what it does, I've included the
man page below.
Rich.
----------------------------------------------------------------------
virt-format(1) Virtualization Support virt-format(1)
NAME
virt-format - Erase and make a blank disk
SYNOPSIS
virt-format [--options] -a disk.img [-a disk.img ...]
DESCRIPTION
Virt-format takes an existing disk file (or it can be a host partition,
LV etc), 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
virt-make-fs(1). If you are creating a blank disk to use in
guestfish(1), you should instead use the guestfish -N option.
Normal usage would be something like this:
virt-format -a disk.qcow
or this:
virt-format -a /dev/VG/LV
"disk.qcow" or "/dev/VG/LV" must exist already. Any
data on these
disks will be erased by these commands. These commands will create a
single empty MBR 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:
--filesystem=[ext3|ntfs|vfat|...]
Create an empty filesystem ("ext3", "ntfs" etc)
inside the
partition.
--lvm[=/dev/VG/LV]
Create a Linux LVM2 logical volume on the disk. When used with
--filesystem, the filesystem is created inside the LV.
For more information about these and other options, see
"OPTIONS"
below.
The format of the disk is normally auto-detected, but you can also
force it by using the --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.
OPTIONS
--help
Display brief help.
-a file
--add file
Add 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 --format=.. option.
Any existing data on the disk is erased.
--filesystem=ext3|ntfs|vfat|...
Create an empty filesystem of the specified type. Many filesystem
types are supported by libguestfs.
--filesystem=none
Create no filesystem. This is the default.
--format=raw|qcow2|..
--format
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.
For example:
virt-format --format=raw -a disk.img
forces raw format (no auto-detection) for "disk.img".
virt-format --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).
--lvm=/dev/VG/LV
Create a Linux LVM2 logical volume called "/dev/VG/LV".
You can
change the name of the volume group and logical volume.
--lvm
Create a Linux LVM2 logical volume with the default name
("/dev/VG/LV").
--lvm=none
Create no logical volume. This is the default.
--partition=gpt
Create a GPT partition instead of MBR. This is useful for disks
which are 2TB or larger in size.
--partition
--partition=mbr
Create an MBR partition. This is the default.
--partition=none
Create no partition table. Note that Windows may not be able to
see these disks.
-v
--verbose
Enable verbose messages for debugging.
-V
--version
Display version number and exit.
--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.
-x Enable tracing of libguestfs API calls.
EXIT STATUS
This program returns 0 on success, or 1 on failure.
SEE ALSO
guestfs(3), guestfish(1), virt-filesystems(1), virt-make-fs(1),
virt-rescue(1), virt-resize(1), <http://libguestfs.org/>.
AUTHOR
Richard W.M. Jones <http://people.redhat.com/~rjones/>
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.
libguestfs-1.15.16 2012-01-17 virt-format(1)
Richard W.M. Jones
2012-Jan-17 17:48 UTC
[Libguestfs] [PATCH] New tool: virt-format: erase and make blank disks.
From: "Richard W.M. Jones" <rjones at redhat.com>
This tool allows you to easily reformat a disk, creating a blank disk
with optional partition, LVM and empty filesystem.
---
.gitignore | 4 +
Makefile.am | 3 +-
configure.ac | 1 +
format/Makefile.am | 78 +++++++++
format/format.c | 438 +++++++++++++++++++++++++++++++++++++++++++++++
format/virt-format.pod | 203 ++++++++++++++++++++++
po/POTFILES.in | 1 +
src/guestfs.pod | 5 +
tests/extra/Makefile.am | 1 +
tools/virt-make-fs | 3 +
10 files changed, 736 insertions(+), 1 deletions(-)
create mode 100644 format/Makefile.am
create mode 100644 format/format.c
create mode 100755 format/virt-format.pod
diff --git a/.gitignore b/.gitignore
index 0611975..36411aa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -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
diff --git a/Makefile.am b/Makefile.am
index d14cc12..22ae04e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -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 \
diff --git a/configure.ac b/configure.ac
index d8abf71..fa97479 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1018,6 +1018,7 @@ AC_CONFIG_FILES([Makefile
erlang/examples/Makefile
examples/Makefile
fish/Makefile
+ format/Makefile
fuse/Makefile
generator/Makefile
gnulib/lib/Makefile
diff --git a/format/Makefile.am b/format/Makefile.am
new file mode 100644
index 0000000..b3ff216
--- /dev/null
+++ b/format/Makefile.am
@@ -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
diff --git a/format/format.c b/format/format.c
new file mode 100644
index 0000000..c264026
--- /dev/null
+++ b/format/format.c
@@ -0,0 +1,438 @@
+/* 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 = "mbr";
+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 = "mbr";
+ 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;
+
+ 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);
+ }
+
+ /* 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))
+ return 1; /* which means, reopen the handle and retry */
+
+ /* Format each disk. */
+ for (i = 0; devices[i] != NULL; ++i) {
+ char *dev = devices[i];
+ int free_dev = 0;
+
+ if (partition) {
+ if (guestfs_part_disk (g, devices[i], partition) == -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);
+ dev = NULL;
+ 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);
+
+ /* Free device list. */
+ for (i = 0; devices[i] != NULL; ++i)
+ free (devices[i]);
+ free (devices);
+
+ return 0;
+}
+
+/* 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;
+}
diff --git a/format/virt-format.pod b/format/virt-format.pod
new file mode 100755
index 0000000..d00dfa6
--- /dev/null
+++ b/format/virt-format.pod
@@ -0,0 +1,203 @@
+=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 MBR 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=gpt>
+
+Create a GPT partition instead of MBR. This is useful for disks which
+are 2TB or larger in size.
+
+=item B<--partition>
+
+=item B<--partition=mbr>
+
+Create an MBR partition. This is the default.
+
+=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.
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 380a3c7..84972db 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -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
diff --git a/src/guestfs.pod b/src/guestfs.pod
index f7740b6..55f6e7f 100644
--- a/src/guestfs.pod
+++ b/src/guestfs.pod
@@ -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)>,
diff --git a/tests/extra/Makefile.am b/tests/extra/Makefile.am
index 8f34958..83abc65 100644
--- a/tests/extra/Makefile.am
+++ b/tests/extra/Makefile.am
@@ -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
diff --git a/tools/virt-make-fs b/tools/virt-make-fs
index d4e231b..3afbb43 100755
--- a/tools/virt-make-fs
+++ b/tools/virt-make-fs
@@ -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)>,
--
1.7.6
On 01/17/2012 07:48 PM, Richard W.M. Jones wrote:> Rather than me explaining over again what it does, I've included the > man page below. > > Rich. > > ---------------------------------------------------------------------- > > virt-format(1) Virtualization Support virt-format(1) > > > > NAME > virt-format - Erase and make a blank disk > > SYNOPSIS > virt-format [--options] -a disk.img [-a disk.img ...] > > DESCRIPTION > Virt-format takes an existing disk file (or it can be a host partition, > LV etc), 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 > virt-make-fs(1). If you are creating a blank disk to use in > guestfish(1), you should instead use the guestfish -N option. > > Normal usage would be something like this: > > virt-format -a disk.qcow > > or this: > > virt-format -a /dev/VG/LV > > "disk.qcow" or "/dev/VG/LV" must exist already. Any data on these > disks will be erased by these commands. These commands will create a > single empty MBR partition covering the whole disk, with no filesystem > inside it.Some thoughts: - does it autodetect when disk is too large for MBR and GPT would be needed? - does it align partitions to SSD erase block size? (LVM is particularly tricky to get right manually) - can I specify a backing-file for qemu disks? (qcow, and qed I think) - can --wipe use TRIM on SSDs instead of writing zeroes? - can I setup LVM striping and mirror with it? If the answer is yes to all these then this tool could even be used as a general purpose format tool, not just for virt environments :) Best regards, --Edwin
Reasonably Related Threads
- [PATCH v2] New tool: virt-format
- [PATCH 1/2] examples: code cleanups
- [PATCH 1/2] Use 'error' function consistently throughout.
- [PATCH] fuse: Add guestmount-cleanup program to handle unmounting (RHBZ#916780).
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