=encoding utf8

=head1 名前

virt-resize - 仮想マシンのディスクの容量変更

=head1 書式

 virt-resize [--resize /dev/sdaN=[+/-]<size>[%]]
   [--expand /dev/sdaN] [--shrink /dev/sdaN]
   [--ignore /dev/sdaN] [--delete /dev/sdaN] [...] indisk outdisk

=head1 説明

Virt-resize is a tool which can resize a virtual machine disk, making it
larger or smaller overall, and resizing or deleting any partitions contained
within.

Virt-resize B<cannot> resize disk images in-place.  Virt-resize B<should
not> be used on live virtual machines - for consistent results, shut the
virtual machine down before resizing it.

If you are not familiar with the associated tools: L<virt-filesystems(1)>
and L<virt-df(1)>, we recommend you go and read those manual pages first.

=head1 例

=over 4

=item 1.

Copy C<olddisk> to C<newdisk>, extending one of the guest's partitions to
fill the extra 5GB of space.

 virt-filesystems --long -h --all -a olddisk
 
 truncate -r olddisk newdisk
 truncate -s +5G newdisk
 
 # "/dev/sda2" は "olddisk" ファイルの中にあるパーティションであることに注意してください。
 virt-resize --expand /dev/sda2 olddisk newdisk

=item 2.

As above, but make the /boot partition 200MB bigger, while giving the
remaining space to /dev/sda2:

 virt-resize --resize /dev/sda1=+200M --expand /dev/sda2 \
   olddisk newdisk

=item 3.

As in the first example, but expand a logical volume as the final step.
This is what you would typically use for Linux guests that use LVM:

 virt-resize --expand /dev/sda2 --LV-expand /dev/vg_guest/lv_root \
   olddisk newdisk

=item 4.

As in the first example, but the output format will be qcow2 instead of a
raw disk:

 qemu-img create -f qcow2 newdisk.qcow2 15G
 virt-resize --expand /dev/sda2 olddisk newdisk.qcow2

=back

=head1 詳細な使用法

=head2 仮想マシンのディスクの拡張方法

=over 4

=item 1. 仮想マシンをシャットダウンします

=item 2. 入力ディスクイメージの位置を探します

Locate the input disk image (ie. the file or device on the host containing
the guest's disk).  If the guest is managed by libvirt, you can use C<virsh
dumpxml> like this to find the disk image name:

 # virsh dumpxml guestname | xpath /domain/devices/disk/source
 Found 1 nodes:
 -- NODE --
 <source dev="/dev/vg/lv_guest" />

=item 3. 現在の容量を確認します

Use L<virt-filesystems(1)> to display the current partitions and sizes:

 # virt-filesystems --long --parts --blkdevs -h -a /dev/vg/lv_guest
 Name       Type       Size  Parent
 /dev/sda1  partition  101M  /dev/sda
 /dev/sda2  partition  7.9G  /dev/sda
 /dev/sda   device     8.0G  -

(This example is a virtual machine with an 8 GB disk which we would like to
expand up to 10 GB).

=item 4. 出力ディスクを作成します

Virt-resize cannot do in-place disk modifications.  You have to have space
to store the resized output disk.

To store the resized disk image in a file, create a file of a suitable size:

 # rm -f outdisk
 # truncate -s 10G outdisk

Or use L<lvcreate(1)> to create a logical volume:

 # lvcreate -L 10G -n lv_name vg_name

Or use L<virsh(1)> vol-create-as to create a libvirt storage volume:

 # virsh pool-list
 # virsh vol-create-as poolname newvol 10G

=item 5. 容量を変更します

virt-resize takes two mandatory parameters, the input disk (eg. device or
file) and the output disk.  The output disk is the one created in the
previous step.

 # virt-resize indisk outdisk

This command just copies disk image C<indisk> to disk image C<outdisk>
I<without> resizing or changing any existing partitions.  If C<outdisk> is
larger, then an extra, empty partition is created at the end of the disk
covering the extra space.  If C<outdisk> is smaller, then it will give an
error.

More realistically you'd want to expand existing partitions in the disk
image by passing extra options (for the full list see the L</OPTIONS>
section below).

L</--expand> is the most useful option.  It expands the named partition
within the disk to fill any extra space:

 # virt-resize --expand /dev/sda2 indisk outdisk

(In this case, an extra partition is I<not> created at the end of the disk,
because there will be no unused space).

L</--resize> is the other commonly used option.  The following would
increase the size of /dev/sda1 by 200M, and expand /dev/sda2 to fill the
rest of the available space:

 # virt-resize --resize /dev/sda1=+200M --expand /dev/sda2 \
     indisk outdisk

If the expanded partition in the image contains a filesystem or LVM PV, then
if virt-resize knows how, it will resize the contents, the equivalent of
calling a command such as L<pvresize(8)>, L<resize2fs(8)>, L<ntfsresize(8)>
or L<btrfs(8)>.  However virt-resize does not know how to resize some
filesystems, so you would have to online resize them after booting the
guest.

Other options are covered below.

=item 6. テストします

Thoroughly test the new disk image I<before> discarding the old one.

If you are using libvirt, edit the XML to point at the new disk:

 # virsh edit guestname

Change E<lt>source ...E<gt>, see
L<http://libvirt.org/formatdomain.html#elementsDisks>

Then start up the domain with the new, resized disk:

 # virsh start guestname

and check that it still works.  See also the L</NOTES> section below for
additional information.

=item 7. Resize LVs etc inside the guest

(This can also be done offline using L<guestfish(1)>)

Once the guest has booted you should see the new space available, at least
for filesystems that virt-resize knows how to resize, and for PVs.  The user
may need to resize LVs inside PVs, and also resize filesystem types that
virt-resize does not know how to expand.

=back

=head2 仮想マシンのディスクの縮小

縮小は拡張よりもいくらか複雑です。ここでは概要のみを示します。

Firstly virt-resize will not attempt to shrink any partition content (PVs,
filesystems).  The user has to shrink content before passing the disk image
to virt-resize, and virt-resize will check that the content has been shrunk
properly.

(Shrinking can also be done offline using L<guestfish(1)>)

After shrinking PVs and filesystems, shut down the guest, and proceed with
steps 3 and 4 above to allocate a new disk image.

Then run virt-resize with any of the I<--shrink> and/or I<--resize> options.

=head2 IGNORING OR DELETING PARTITIONS

virt-resize also gives a convenient way to ignore or delete partitions when
copying from the input disk to the output disk.  Ignoring a partition speeds
up the copy where you don't care about the existing contents of a
partition.  Deleting a partition removes it completely, but note that it
also renumbers any partitions after the one which is deleted, which can
leave some guests unbootable.

=head2 QCOW2 AND NON-SPARSE RAW FORMATS

If the input disk is in qcow2 format, then you may prefer that the output is
in qcow2 format as well.  Alternately, virt-resize can convert the format on
the fly.  The output format is simply determined by the format of the empty
output container that you provide.  Thus to create qcow2 output, use:

 qemu-img create [-c] -f qcow2 outdisk [size]

instead of the truncate command (use I<-c> for a compressed disk).

Similarly, to get non-sparse raw output use:

 fallocate -l size outdisk

(on older systems that don't have the L<fallocate(1)> command use C<dd
if=/dev/zero of=outdisk bs=1M count=..>)

=head2 論理パーティション

論理パーティション（DOS パーティションテーブルを使用しているディスクにおいて C</dev/sda5+> とも言う）は容量変更できません。

To understand what is going on, firstly one of the four partitions
C</dev/sda1-4> will have MBR partition type C<05> or C<0f>.  This is called
the B<extended partition>.  Use L<virt-filesystems(1)> to see the MBR
partition type.

Logical partitions live inside the extended partition.

The extended partition can be expanded, but not shrunk (unless you force it,
which is not advisable).  When the extended partition is copied across, all
the logical partitions contained inside are copied over implicitly.
Virt-resize does not look inside the extended partition, so it copies the
logical partitions blindly.

You cannot specify a logical partition (C</dev/sda5+>) at all on the command
line.  Doing so will give an error.

=head1 オプション

=over 4

=item B<--help>

ヘルプを表示します。

=item B<--align-first auto>

=item B<--align-first never>

=item B<--align-first always>

Align the first partition for improved performance (see also the
I<--alignment> option).

The default is I<--align-first auto> which only aligns the first partition
if it is safe to do so.  That is, only when we know how to fix the
bootloader automatically, and at the moment that can only be done for
Windows guests.

I<--align-first never> means we never move the first partition.  This is the
safest option.  Try this if the guest does not boot after resizing.

I<--align-first always> means we always align the first partition (if it
needs to be aligned).  For some guests this will break the bootloader,
making the guest unbootable.

=item B<--alignment N>

Set the alignment of partitions to C<N> sectors.  The default in virt-resize
E<lt> 1.13.19 was 64 sectors, and after that is 128 sectors.

Assuming 512 byte sector size inside the guest, here are some suitable
values for this:

=over 4

=item I<--alignment 1> (512 バイト)

The partitions would be packed together as closely as possible, but would be
completely unaligned.  In some cases this can cause very poor performance.
See L<virt-alignment-scan(1)> for further details.

=item I<--alignment 8> (4K)

This would be the minimum acceptable alignment for reasonable performance on
modern hosts.

=item I<--alignment 128> (64K)

This alignment provides good performance when the host is using high end
network storage.

=item I<--alignment 2048> (1M)

This is the standard alignment used by all newly installed guests since
around 2008.

=back

=item B<-d>

=item B<--debug>

デバッグメッセージを有効にします。

=item B<--debug-gc>

Debug garbage collection and memory allocation.  This is only useful when
debugging memory problems in virt-resize or the OCaml libguestfs bindings.

=item B<--delete part>

Delete the named partition.  It would be more accurate to describe this as
"don't copy it over", since virt-resize doesn't do in-place changes and the
original disk image is left intact.

Note that when you delete a partition, then anything contained in the
partition is also deleted.  Furthermore, this causes any partitions that
come after to be I<renumbered>, which can easily make your guest unbootable.

このオプションは複数回指定できます。

=item B<--expand part>

Expand the named partition so it uses up all extra space (space left over
after any other resize changes that you request have been done).

If virt-resize knows how, it will expand the direct content of the
partition.  For example, if the partition is an LVM PV, it will expand the
PV to fit (like calling L<pvresize(8)>).  Virt-resize leaves any other
content it doesn't know about alone.

Currently virt-resize can resize:

=over 4

=item *

ext2, ext3, ext4 ファイルシステム。

=item *

NTFS filesystems, if libguestfs was compiled with support for NTFS.

The filesystem must have been shut down consistently last time it was used.
Additionally, L<ntfsresize(8)> marks the resized filesystem as requiring a
consistency check, so at the first boot after resizing Windows will check
the disk.

=item *

LVM PVs (physical volumes).  virt-resize does not usually resize anything
inside the PV, but see the I<--LV-expand> option.  The user could also
resize LVs as desired after boot.

=item *

Btrfs filesystems, if libguestfs was compiled with support for btrfs.

=back

Note that you cannot use I<--expand> and I<--shrink> together.

=item B<--format> raw

Specify the format of the input disk image.  If this flag is not given then
it is auto-detected from the image itself.

If working with untrusted raw-format guest disk images, you should ensure
the format is always specified.

Note that this option I<does not> affect the output format.  See L</QCOW2
AND NON-SPARSE RAW FORMATS>.

=item B<--ignore part>

Ignore the named partition.  Effectively this means the partition is
allocated on the destination disk, but the content is not copied across from
the source disk.  The content of the partition will be blank (all zero
bytes).

このオプションは複数回指定できます。

=item B<--LV-expand logvol>

This takes the logical volume and, as a final step, expands it to fill all
the space available in its volume group.  A typical usage, assuming a Linux
guest with a single PV C</dev/sda2> and a root device called
C</dev/vg_guest/lv_root> would be:

 virt-resize indisk outdisk \
   --expand /dev/sda2 --LV-expand /dev/vg_guest/lv_root

This would first expand the partition (and PV), and then expand the root
device to fill the extra space in the PV.

The contents of the LV are also resized if virt-resize knows how to do
that.  You can stop virt-resize from trying to expand the content by using
the option I<--no-expand-content>.

仮想マシンにあるファイルシステムを一覧表示するには L<virt-filesystems(1)> を使用します。

You can give this option multiple times, I<but> it doesn't make sense to do
this unless the logical volumes you specify are all in different volume
groups.

=item B<--machine-readable>

このオプションは、他のプログラムにより解析されるときに、よりマシンに易しい出力を作成するために使用されます。以下の L</マシン可読な出力> 参照。

=item B<-n>

=item B<--dryrun>

Print a summary of what would be done, but don't do anything.

=item B<--no-copy-boot-loader>

By default, virt-resize copies over some sectors at the start of the disk
(up to the beginning of the first partition).  Commonly these sectors
contain the Master Boot Record (MBR) and the boot loader, and are required
in order for the guest to boot correctly.

If you specify this flag, then this initial copy is not done.  You may need
to reinstall the boot loader in this case.

=item B<--no-extra-partition>

By default, virt-resize creates an extra partition if there is any extra,
unused space after all resizing has happened.  Use this option to prevent
the extra partition from being created.  If you do this then the extra space
will be inaccessible until you run fdisk, parted, or some other partitioning
tool in the guest.

Note that if the surplus space is smaller than 10 MB, no extra partition
will be created.

=item B<--no-expand-content>

By default, virt-resize will try to expand the direct contents of
partitions, if it knows how (see I<--expand> option above).

I<--no-expand-content> オプションを指定すると、virt-resize はこれを試行しません。

=item B<--ntfsresize-force>

L<ntfsresize(8)> に I<--force> オプションを渡します。これにより、NTFS
ディスクが整合性の確認が必要であるという印をつけたときでも、容量の変更を許可します。Windows
仮想マシンを各容量において起動することなく、何回も容量変更したいならば、このオプションを使用する必要があります。

=item B<--output-format> raw

Specify the format of the output disk image.  If this flag is not given then
it is auto-detected from the image itself.

If working with untrusted raw-format guest disk images, you should ensure
the format is always specified.

Note that this option I<does not create> the output format.  This option
just tells libguestfs what it is so it doesn't try to guess it.  You still
need to create the output disk with the right format.  See L</QCOW2 AND
NON-SPARSE RAW FORMATS>.

=item B<-q>

=item B<--quiet>

概要を表示しません。

=item B<--resize part=size>

Resize the named partition (expanding or shrinking it) so that it has the
given size.

C<size> は b/K/M/G
が後につく絶対値として表現されます。それぞれ、バイト、キロバイト、メガバイト、ギガバイトを意味します。または、現在の容量に対する割合、相対的な数値、パーセントとして表現されます。たとえば:

 --resize /dev/sda2=10G

 --resize /dev/sda4=90%

 --resize /dev/sda2=+1G

 --resize /dev/sda2=-200M

 --resize /dev/sda1=+128K

 --resize /dev/sda1=+10%

 --resize /dev/sda1=-10%

あらゆるパーティションの容量を拡大できます。virt-resize は、どのように拡大するかわかれば（以下の I<--expand>
参照）、パーティションの内容を直接拡大します。

You can only I<decrease> the size of partitions that contain filesystems or
PVs which have already been shrunk.  Virt-resize will check this has been
done before proceeding, or else will print an error (see also
I<--resize-force>).

このオプションは複数回指定できます。

=item B<--resize-force part=size>

This is the same as I<--resize> except that it will let you decrease the
size of any partition.  Generally this means you will lose any data which
was at the end of the partition you shrink, but you may not care about that
(eg. if shrinking an unused partition, or if you can easily recreate it such
as a swap partition).

I<--ignore> オプション参照。

=item B<--shrink part>

Shrink the named partition until the overall disk image fits in the
destination.  The named partition B<must> contain a filesystem or PV which
has already been shrunk using another tool (eg. L<guestfish(1)> or other
online tools).  Virt-resize will check this and give an error if it has not
been done.

The amount by which the overall disk must be shrunk (after carrying out all
other operations requested by the user) is called the "deficit".  For
example, a straight copy (assume no other operations)  from a 5GB disk image
to a 4GB disk image results in a 1GB deficit.  In this case, virt-resize
would give an error unless the user specified a partition to shrink and that
partition had more than a gigabyte of free space.

Note that you cannot use I<--expand> and I<--shrink> together.

=item B<-V>

=item B<--version>

バージョン番号を表示して終了します。

=back

=head1 マシン可読な出力

I<--machine-readable> オプションはよりマシンに易しい出力を作成するために使用できます。これは他のプログラムや GUI などから
virt-resize を呼び出すときに有用です。

このオプションを使用するには 2 通りの方法があります。

Firstly use the option on its own to query the capabilities of the
virt-resize binary.  Typical output looks like this:

 $ virt-resize --machine-readable
 virt-resize
 ntfsresize-force
 32bitok
 ntfs
 btrfs

A list of features is printed, one per line, and the program exits with
status 0.

Secondly use the option in conjunction with other options to make the
regular program output more machine friendly.

At the moment this means:

=over 4

=item 1.

Progress bar messages can be parsed from stdout by looking for this regular
expression:

 ^[0-9]+/[0-9]+$

=item 2.

The calling program should treat messages sent to stdout (except for
progress bar messages) as status messages.  They can be logged and/or
displayed to the user.

=item 3.

The calling program should treat messages sent to stderr as error messages.
In addition, virt-resize exits with a non-zero status code if there was a
fatal error.

=back

Versions of the program prior to 1.13.9 did not support the
I<--machine-readable> option and will return an error.

=head1 注記

=head2 "Partition 1 does not end on cylinder boundary."

Virt-resize aligns partitions to multiples of 128 sectors (see the
I<--alignment> parameter).  Usually this means the partitions will not be
aligned to the ancient CHS geometry.  However CHS geometry is meaningless
for disks manufactured since the early 1990s, and doubly so for virtual hard
drives.  Alignment of partitions to cylinders is not required by any modern
operating system.

=head2 RESIZING WINDOWS VIRTUAL MACHINES

In Windows Vista and later versions, Microsoft switched to using a separate
boot partition.  In these VMs, typically C</dev/sda1> is the boot partition
and C</dev/sda2> is the main (C:) drive.  Resizing the first (boot)
partition causes the bootloader to fail with C<0xC0000225> error.  Resizing
the second partition (ie. C: drive)  should work.

Windows may initiate a lengthy "chkdsk" on first boot after a resize, if
NTFS partitions have been expanded.  This is just a safety check and (unless
it find errors) is nothing to worry about.

=head2 GUEST BOOT STUCK AT "GRUB"

If a Linux guest does not boot after resizing, and the boot is stuck after
printing C<GRUB> on the console, try reinstalling grub.

 guestfish -i -a newdisk
 ><fs> cat /boot/grub/device.map
 # check the contents of this file are sensible or
 # edit the file if necessary
 ><fs> grub-install / /dev/vda
 ><fs> exit

For more flexible guest reconfiguration, including if you need to specify
other parameters to grub-install, use L<virt-rescue(1)>.

=head2 Windows UNMOUNTABLE_BOOT_VOLUME BSOD

Windows 仮想マシンを sysprep して、virt-resize を用いて容量を変更した後、仮想マシンが
C<UNMOUNTABLE_BOOT_VOLUME> BSOD で起動に失敗するかもしれません。このエラーは sysprep.inf ファイルに
C<ExtendOemPartition=1> があることにより引き起こされます。sysprep
する前にこの行を削除することにより、この問題を解決できます。

=head1 代替ツール

There are several proprietary tools for resizing partitions.  We won't
mention any here.

L<parted(8)> and its graphical shell gparted can do some types of resizing
operations on disk images.  They can resize and move partitions, but I don't
think they can do anything with the contents, and they certainly don't
understand LVM.

L<guestfish(1)> can do everything that virt-resize can do and a lot more,
but at a much lower level.  You will probably end up hand-calculating sector
offsets, which is something that virt-resize was designed to avoid.  If you
want to see the guestfish-equivalent commands that virt-resize runs, use the
I<--debug> flag.

=head1 SHELL QUOTING

Libvirt guest names can contain arbitrary characters, some of which have
meaning to the shell such as C<#> and space.  You may need to quote or
escape these characters on the command line.  See the shell manual page
L<sh(1)> for details.

=head1 終了ステータス

このプログラムは、成功すると 0 を、エラーがあると 0 以外を返します。

=head1 関連項目

L<virt-filesystems(1)>, L<virt-df(1)>, L<guestfs(3)>, L<guestfish(1)>,
L<lvm(8)>, L<pvresize(8)>, L<lvresize(8)>, L<resize2fs(8)>,
L<ntfsresize(8)>, L<btrfs(8)>, L<virsh(1)>, L<parted(8)>, L<truncate(1)>,
L<fallocate(1)>, L<grub(8)>, L<grub-install(8)>, L<virt-rescue(1)>,
L<virt-sparsify(1)>, L<virt-alignment-scan(1)>, L<http://libguestfs.org/>.

=head1 著者

Richard W.M. Jones L<http://people.redhat.com/~rjones/>

=head1 COPYRIGHT

Copyright (C) 2010-2012 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.