名前

       virt-diff - Differences between files in two virtual machines

書式

        virt-diff [--options] -d domain1 -D domain2

        virt-diff [--options] -a disk1.img [-a ...] -A disk2.img [-A ...]

説明

       "virt-diff" lists the differences between files in two virtual machines or disk images.
       The usual use case is to show the changes in a VM after it has been running for a while,
       by taking a snapshot, running the VM, and then using this tool to show what changed
       between the new VM state and the old snapshot.

       This tool will find differences in filenames, file sizes, checksums, extended attributes,
       file content and more from a virtual machine or disk image.  However it does not look at
       the boot loader, unused space between partitions or within filesystems, "hidden" sectors
       and so on.  In other words, it is not a security or forensics tool.

       To specify two guests, you have to use the -a or -d option(s)  for the first guest, and
       the -A or -D option(s) for the second guest.  The common case is:

        virt-diff -a old.img -A new.img

       or using names known to libvirt:

        virt-diff -d oldguest -D newguest

オプション

       --help
           簡単なヘルプを表示します。

       -a file
       --add file
           Add file which should be a disk image from the first virtual machine.  If the virtual
           machine has multiple block devices, you must supply all of them with separate -a
           options.

           ディスクイメージの形式は自動検知されます。 これを上書きして強制的に特定の形式を使用す
           る場合、 --format=.. オプションを使用します。

       -a URI
       --add URI
           リモートディスクを追加します。 "リモートストレージの追加" in guestfish(1) 参照。

       --all
           Same as --extra-stats --times --uids --xattrs.

       --atime
           The default is to ignore changes in file access times, since those are unlikely to be
           interesting.  Using this flag shows atime differences as well.

       -A file
       -A URI
           Add a disk image from the second virtual machine.

       --checksum
       --checksum=crc|md5|sha1|sha224|sha256|sha384|sha512
           Use a checksum over file contents to detect when regular files have changed content.

           With no argument, this defaults to using md5.  Using an argument, you can select the
           checksum type to use.  If the flag is omitted then file times and size are used to
           determine if a file has changed.

       -c URI
       --connect URI
           libvirt を使用していると、指定された URI に接続します。  省略すると、デフォルトの
           libvirt ハイパーバイザーに接続します。

           ゲストのブロックデバイスを直接指定していると（(-a)）、libvirt は何も使用されません。

       --csv
           Write out the results in CSV format (comma-separated values).  This format can be
           imported easily into databases and spreadsheets, but read "NOTE ABOUT CSV FORMAT"
           below.

       --dir-links
           The default is to ignore changed in the number of links in directory entries, since
           those are unlikely to be interesting.  Using this flag shows changes to the nlink
           field of directories.

       --dir-times
           The default is to ignore changed times on directory entries, since those are unlikely
           to be interesting.  Using this flag shows changes to the time fields of directories.

       -d guest
       --domain guest
           Add all the disks from the named libvirt guest, as the first guest.  Domain UUIDs can
           be used instead of names.

       -D guest
           Add all the disks from the named libvirt guest, as the second guest.  Domain UUIDs can
           be used instead of names.

       --echo-keys
           When prompting for keys and passphrases, virt-diff normally turns echoing off so you
           cannot see what you are typing.  If you are not worried about Tempest attacks and
           there is no one else in the room you can specify this flag to see what you are typing.

       --extra-stats
           Display extra stats.

       --format=raw|qcow2|..
       --format
           The default for the -a/-A option is to auto-detect the format of the disk image.
           Using this forces the disk format for -a/-A options which follow on the command line.
           Using --format with no argument switches back to auto-detection for subsequent -a/-A
           options.

           例:

            virt-diff --format=raw -a disk.img [...]

           forces raw format (no auto-detection) for disk.img.

            virt-diff --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.

           仮想マシンのディスクイメージが信頼できない raw 形式である場合、 ディスク形式を指定する
           ためにこのオプションを使用すべきです。 これにより、悪意のある仮想マシンにより起こり得
           る セキュリティ問題を回避できます (CVE-2010-3851)。

       -h
       --human-readable
           読みやすい形式でファイル容量を表示します。

       --keys-from-stdin
           Read key or passphrase parameters from stdin.  The default is to try to read
           passphrases from the user by opening /dev/tty.

       --times
           時間の項目を表示します。

       --time-days
           Display time fields as days before now (negative if in the future).

           Note that 0 in output means "up to 1 day before now", or that the age of the file is
           between 0 and 86399 seconds.

       --time-relative
           Display time fields as seconds before now (negative if in the future).

       --time-t
           Display time fields as seconds since the Unix epoch.

       --uids
           UID と GID の項目を表示します。

       -v
       --verbose
           デバッグ用の冗長な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。

       --xattrs
           Display extended attributes.

CSV 形式に関する注意

       Comma-separated values (CSV) is a deceptive format.  It seems like it should be easy to
       parse, but it is definitely not easy to parse.

       神話: ただコンマで項目を区切る。 真実: これは正しく動き ません。この例は 2 つの列がありま
       す:

        "foo,bar",baz

       神話: 同時にファイルの 1 行を読み込みます。 真実: これは正しく動き ません。この例は 1 つの
       行があります:

        "foo
        bar",baz

       For shell scripts, use "csvtool" (https://github.com/Chris00/ocaml-csv also packaged in
       major Linux distributions).

       For other languages, use a CSV processing library (eg. "Text::CSV" for Perl or Python's
       built-in csv library).

       Most spreadsheets and databases can import CSV directly.

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

       guestfs(3), guestfish(1), virt-cat(1), virt-copy-out(1), virt-ls(1), virt-tar-out(1),
       http://libguestfs.org/.

著者

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

COPYRIGHT

       Copyright (C) 2009-2017 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.