bionic (1) virt-resize.1.gz

Provided by: libguestfs-tools_1.36.13-1ubuntu3.3_amd64 bug

名前

       virt-resize - 仮想マシンのディスクの容量変更

書式

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

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 cannot resize disk images in-place.  Virt-resize 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: virt-filesystems(1) and virt-df(1), we recommend you
       go and read those manual pages first.

       1.  This example takes "olddisk" and resizes it into "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

       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

       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

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

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

詳細な使用法

   仮想マシンのディスクの拡張方法
       1. 仮想マシンをシャットダウンします
       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 "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" />

       3. 現在の容量を確認します
           現在のパーティションおよび容量を表示するには virt-filesystems(1) を使用します:

            # 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).

       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

           または、論理ボリュームを作成するために lvcreate(1) を使用します:

            # lvcreate -L 10G -n lv_name vg_name

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

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

       5. 容量を変更します
           virt-resize takes two mandatory parameters, the input disk and the output disk (both can be e.g. a
           device, a file, or a URI to a remote disk).  The output disk is the one created in the previous step.

            # virt-resize indisk outdisk

           This command just copies disk image "indisk" to disk image "outdisk" without resizing or changing any
           existing partitions.  If "outdisk" is larger, then an extra, empty partition is created at the end of
           the disk covering the extra space.  If "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 "OPTIONS" section below).

           "--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 not created at the end of the disk, because there will be no
           unused space).

           "--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 pvresize(8),
           resize2fs(8), ntfsresize(8), btrfs(8) or xfs_growfs(8).  However virt-resize does not know how to
           resize some filesystems, so you would have to online resize them after booting the guest.

            # virt-resize --expand /dev/sda2 nbd://example.com outdisk

           The input disk can be a URI, in order to use a remote disk as the source.  The URI format is
           compatible with guestfish.  See "ADDING REMOTE STORAGE" in guestfish(1).

           他のオプションは以下に記載しています。

       6. テストします
           Thoroughly test the new disk image before discarding the old one.

           libvirt を使用しているならば、新しいディスクを指し示すよう XML を編集します:

            # virsh edit guestname

           <source ...> を変更します、http://libvirt.org/formatdomain.html#elementsDisks を参照してください。

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

            # virsh start guestname

           and check that it still works.  See also the "NOTES" section below for additional information.

       7. Resize LVs etc inside the guest
           (This can also be done offline using 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.

   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 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 --shrink and/or --resize options.

   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.

   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 -f qcow2 -o preallocation=metadata outdisk [size]

       instead of the truncate command.

       Similarly, to get non-sparse raw output use:

        fallocate -l size outdisk

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

   論理パーティション
       Logical partitions (a.k.a. /dev/sda5+ on disks using DOS partition tables) cannot be resized.

       To understand what is going on, firstly one of the four partitions /dev/sda1-4 will have MBR partition
       type 05 or "0f".  This is called the extended partition.  Use 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 (/dev/sda5+) at all on the command line.  Doing so will give an
       error.

オプション

       --help
           ヘルプを表示します。

       --align-first auto
       --align-first never
       --align-first always
           Align the first partition for improved performance (see also the --alignment option).

           The default is --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.

           --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.

           --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.

       --alignment N
           Set the alignment of partitions to "N" sectors.  The default in virt-resize < 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:

           --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 virt-alignment-scan(1) for
               further details.

           --alignment 8 (4K)
               This would be the minimum acceptable alignment for reasonable performance on modern hosts.

           --alignment 128 (64K)
               This alignment provides good performance when the host is using high end network storage.

           --alignment 2048 (1M)
               This is the standard alignment used by all newly installed guests since around 2008.

       --colors
       --colours
           Use ANSI colour sequences to colourize messages.  This is the default when the output is a tty.  If
           the output of the program is redirected to a file, ANSI colour sequences are disabled unless you use
           this option.

       -d
       --debug
           (Deprecated: use -v option instead)

           デバッグメッセージを有効にします。

       --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 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。

       --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 pvresize(8)).  Virt-resize leaves
           any other content it doesn't know about alone.

           Currently virt-resize can resize:

           •   ext2, ext3, ext4 ファイルシステム。

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

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

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

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

           •   XFS filesystems, if libguestfs was compiled with support for XFS.

           •   Linux swap partitions.

               Please note that libguestfs destroys the existing swap content by recreating it with "mkswap", so
               this should not be used when the guest is suspended.

           Note that you cannot use --expand and --shrink together.

       --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 does not affect the output format.  See "QCOW2 AND NON-SPARSE RAW FORMATS".

       --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。

       --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 /dev/sda2 and a root device
           called /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 --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 virt-filesystems(1) を使用します。

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

       --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 "マシン可読な出力" 参照。

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

       --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.

       --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.

       --no-expand-content
           By default, virt-resize will try to expand the direct contents of partitions, if it knows how (see
           --expand option above).

           --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。

       --no-sparse
           Turn off sparse copying.  See "SPARSE COPYING" below.

       --ntfsresize-force
           ntfsresize(8) に --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。

       --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 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 "QCOW2 AND NON-SPARSE RAW FORMATS".

       -q
       --quiet
           概要を表示しません。

       --resize PART=SIZE
           Resize the named partition (expanding or shrinking it) so that it has the given size.

           "SIZE" can be expressed as an absolute number followed by b/K/M/G to mean bytes, Kilobytes,
           Megabytes, or Gigabytes; or as a percentage of the current size; or as a relative number or
           percentage.  For example:

            --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%

           You can increase the size of any partition.  Virt-resize will expand the direct content of the
           partition if it knows how (see --expand above).

           You can only 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 --resize-force).

           このオプションは複数回指定できます。

       --resize-force PART=SIZE
           This is the same as --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).

           --ignore オプション参照。

       --shrink PART
           Shrink the named partition until the overall disk image fits in the destination.  The named partition
           must contain a filesystem or PV which has already been shrunk using another tool (eg. 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 --expand and --shrink together.

       --unknown-filesystems ignore
       --unknown-filesystems warn
       --unknown-filesystems error
           Configure the behaviour of virt-resize when asking to expand a filesystem, and neither libguestfs has
           the support it, nor virt-resize knows how to expand the content of the filesystem.

           --unknown-filesystems ignore will cause virt-resize to silently ignore such filesystems, and nothing
           is printed about them.

           --unknown-filesystems warn (the default behaviour) will cause virt-resize to warn for each of the
           filesystem that cannot be expanded, but still continuing to resize the disk.

           --unknown-filesystems error will cause virt-resize to error out at the first filesystem that cannot
           be expanded.

           See also "unknown/unavailable method for expanding the TYPE filesystem on DEVICE/LV".

       -v
       --verbose
           デバッグメッセージを有効にします。

       -V
       --version
           バージョン番号を表示して、終了します。

       -x  libguestfs API 呼び出しのトレースを有効にします。

マシン可読な出力

       --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:

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

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

       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.

       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.

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

注記

   "Partition 1 does not end on cylinder boundary."
       Virt-resize aligns partitions to multiples of 128 sectors (see the --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.

   GUEST BOOT STUCK AT "GRUB"
       If a Linux guest does not boot after resizing, and the boot is stuck after printing "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 virt-rescue(1).

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

   WINDOWS CHKDSK
       Windows disks which use NTFS must be consistent before virt-resize can be used.  If the ntfsresize
       operation fails, try booting the original VM and running "chkdsk /f" on all NTFS partitions, then shut
       down the VM cleanly.  For further information see: https://bugzilla.redhat.com/show_bug.cgi?id=975753

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

   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
       "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
       "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。

   WINDOWS 8
       Windows 8 "fast startup" can prevent virt-resize from resizing NTFS partitions.  See "WINDOWS HIBERNATION
       AND WINDOWS 8 FAST STARTUP" in guestfs(3).

   SPARSE COPYING
       You should create a fresh, zeroed target disk image for virt-resize to use.

       Virt-resize by default performs sparse copying.  This means that it does not copy blocks from the source
       disk which are all zeroes.  This improves speed and efficiency, but will produce incorrect results if the
       target disk image contains unzeroed data.

       The main time this can be a problem is if the target is a host partition (eg.
       "virt-resize source.img /dev/sda4") because the usual partitioning tools tend to leave whatever data
       happened to be on the disk before.

       If you have to reuse a target which contains data already, you should use the --no-sparse option.  Note
       this can be much slower.

   "unknown/unavailable method for expanding the TYPE filesystem on DEVICE/LV"
       Virt-resize was asked to expand a partition or a logical volume containing a filesystem with the type
       "TYPE", but there is no available nor known expanding method for that filesystem.

       This may be due to either of the following:

       1.  There corresponding filesystem is not available in libguestfs, because there is no proper package in
           the host with utilities for it.  This is usually the case for "btrfs", "ntfs", and "xfs" filesystems.

           Check the results of:

            virt-resize --machine-readable
            guestfish -a /dev/null run : available
            guestfish -a /dev/null run : filesystem_available TYPE

           In this case, it is enough to install the proper packages adding support for them.  For example,
           "libguestfs-xfs" on Red Hat Enterprise Linux, CentOS, Debian, Ubuntu, and distributions derived from
           them, for supporting the "xfs" filesystem.

       2.  Virt-resize has no support for expanding that type of filesystem.

           In this case, there's nothing that can be done to let virt-resize expand that type of filesystem.

       In both cases, virt-resize will not expand the mentioned filesystem; the result (unless
       --unknown-filesystems error is specified)  is that the partitions containing such filesystems will be
       actually bigger as requested, but the filesystems will still be usable at the their older sizes.

代替ツール

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

       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.

       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 --debug flag.

       dracut(8) includes a module called "dracut-modules-growroot" which can be used to grow the root partition
       when the guest first boots up.  There is documentation for this module in an associated README file.

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。

関連項目

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

著者

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

       Copyright (C) 2010-2012 Red Hat Inc.

LICENSE

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.