guestmount(1)

НАЗВА
guestmount - Mount a guest filesystem on the host using FUSE and libguestfs

КОРОТКИЙ ОПИС
 guestmount [--options] -a disk.img -m device [--ro] mountpoint

 guestmount [--options] -a disk.img -i [--ro] mountpoint

 guestmount [--options] -d Guest -i [--ro] mountpoint

ОПИС
The guestmount program can be used to mount virtual machine filesystems and other disk images on the host. It uses libguestfs for access to the guest filesystem, and FUSE (the "filesystem in userspace") to make it appear as a mountable device.

Along with other options, you have to give at least one device (-a option) or libvirt domain (-d option), and at least one mountpoint (-m option) or use the -i inspection option or the --live option. How this works is better explained in the guestfish(1) manual page, or by looking at the examples below.

FUSE lets you mount filesystems as non-root. The mountpoint must be owned by you. The filesystem will not be visible to any other users unless you make configuration changes, see "NOTES" below.

To unmount the filesystem, use the guestunmount(1) command.

ПРИКЛАДИ
For a typical Windows guest which has its main filesystem on the first partition:

 guestmount -a windows.img -m /dev/sda1 --ro /mnt

For a typical Linux guest which has a /boot filesystem on the first partition, and the root filesystem on a logical volume:

 guestmount -a linux.img -m /dev/VG/LV -m /dev/sda1:/boot --ro /mnt

To get libguestfs to detect guest mountpoints for you:

 guestmount -a guest.img -i --ro /mnt

For a libvirt guest called "Guest" you could do:

 guestmount -d Guest -i --ro /mnt

If you don't know what filesystems are contained in a guest or disk image, use virt-filesystems(1) first:

 virt-filesystems -d MyGuest

If you want to trace the libguestfs calls but without excessive debugging information, we recommend:

 guestmount [...] --trace /mnt

If you want to debug the program, we recommend:

 guestmount [...] --trace --verbose /mnt

To unmount the filesystem after using it:

 guestunmount /mnt

ПРИМІТКИ

  Other users cannot see the filesystem by default
If you mount a filesystem as one user (eg. root), then other users will not be able to see it by default. The fix is to add the FUSE "allow_other" option when mounting:

 sudo guestmount [...] -o allow_other /mnt

and to enable this option in /etc/fuse.conf.

  Enabling FUSE
On some distros, you may need to add yourself to a special group (eg. "fuse") before you can use any FUSE filesystem. This is necessary on Debian and derivatives.

On other distros, no special group is required. It is not necessary on Fedora or Red Hat Enterprise Linux.

  fusermount error: "Device or resource busy"
You can see this error when another process on the system jumps into the mountpoint you have just created, holding it open and preventing you from unmounting it. The usual culprits are various GUI "indexing" programs.

The popular workaround for this problem is to retry the "fusermount -u" command a few times until it works (guestunmount(1) does this for you). Unfortunately this isn't a reliable fix if (for example) the mounted filesystem is particularly large and the intruding program particularly persistent.

A proper fix is to use a private mountpoint by creating a new mount namespace using the Linux-specific clone(2)/unshare(2) flag "CLONE_NEWNS". Unfortunately at the moment this requires root and we would also probably need to add it as a feature to guestmount.

  Race conditions possible when shutting down the connection
When guestunmount(1)/fusermount(1) exits, guestmount may still be running and cleaning up the mountpoint. The disk image will not be fully finalized.

This means that scripts like the following have a nasty race condition:

 guestmount -a disk.img -i /mnt
 # скопіювати дані до /mnt
 guestunmount /mnt
 # негайно спробувати використати 'disk.img' ** НЕБЕЗПЕЧНО **

The solution is to use the --pid-file option to write the guestmount PID to a file, then after guestunmount spin waiting for this PID to exit.

 guestmount -a disk.img -i --pid-file guestmount.pid /mnt

 # ...
 # ...

 # Save the PID of guestmount *before* calling guestunmount.
 pid="$(cat guestmount.pid)"

 # Демонтувати файлову систему.
 guestunmount /mnt

 timeout=10

 count=$timeout
 while kill -0 "$pid" 2>/dev/null && [ $count -gt 0 ]; do
     sleep 1
     ((count--))
 done
 if [ $count -eq 0 ]; then
     echo "$0: wait for guestmount to exit failed after $timeout seconds"
     exit 1
 fi

 # Now it is safe to use the disk image.

Note that if you use the "guestfs_mount_local" API directly (see "MOUNT LOCAL" in guestfs(3)) then it is much easier to write a safe, race-free program.

ПАРАМЕТРИ

-a ОБРАЗ
--add ОБРАЗ
    Add a block device or virtual machine image.

    Формат образу диска визначається автоматично. Щоб перевизначити його і примусово використати певний формат, скористайтеся параметром --format=...

-a адреса
--add адреса
    Додати віддалений диск. Див. "ДОДАВАННЯ ВІДДАЛЕНОГО СХОВИЩА" in guestfish(1).

-c адреса
--connect адреса
    When used in conjunction with the -d option, this specifies the libvirt URI to use. The default is to use the default libvirt connection.

-d ДОМЕН_LIBVIRT
--domain ДОМЕН_LIBVIRT
    Add disks from the named libvirt domain. If the --ro option is also used, then any libvirt domain can be used. However in write mode, only libvirt domains which are shut down can be named here.

    Замість назв можна використовувати UUID доменів.

--dir-cache-timeout N
    Set the readdir cache timeout to N seconds, the default being 60 seconds. The readdir cache [actually, there are several semi-independent caches] is populated after a readdir(2) call with the stat and extended attributes of the files in the directory, in anticipation that they will be requested soon after.

    There is also a different attribute cache implemented by FUSE (see the FUSE option -o attr_timeout), but the FUSE cache does not anticipate future requests, only cache existing ones.

--echo-keys
    When prompting for keys and passphrases, guestfish 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.

--fd=FD
    Specify a pipe or eventfd file descriptor. When the mountpoint is ready to be used, guestmount writes a single byte to this file descriptor. This can be used in conjunction with --no-fork in order to run guestmount captive under another process.

--format=raw|qcow2|..
--format
    Типовим значенням для параметра -a є автоматичне визначення формату образу диска. Використання цього параметра примусово визначає значення параметрів -a формату диска у наступному рядку команди. Використання параметра --format без аргументу перемикає програму у режим автоматичного визначення у наступних параметрах -a.

    Якщо ви користуєтеся ненадійними образами гостьових систем у необробленому форматі, вам слід скористатися цим параметром для визначення формату диска. Таким чином можна уникнути можливих проблем з захистом для сформованих зловмисниками гостьових систем (CVE-2010-3851). Див. також <guestfs(3)/guestfs_add_drive_opts>.

--fuse-help
    Display help on special FUSE options (see -o below).

--help
    Показати короткі довідкові дані і завершити роботу.

-i
--inspector
    Using virt-inspector(1) code, inspect the disks looking for an operating system and mount filesystems as they would be mounted on the real virtual machine.

--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.

--live
    Connect to a live virtual machine. (Experimental, see "ATTACHING TO RUNNING DAEMONS" in guestfs(3)).

-m dev[:mountpoint[:options[:fstype]]
--mount dev[:mountpoint[:options[:fstype]]]
    Mount the named partition or logical volume on the given mountpoint in the guest (this has nothing to do with mountpoints in the host).

    If the mountpoint is omitted, it defaults to /. You have to mount something on /.

    The third (and rarely used) part of the mount parameter is the list of mount options used to mount the underlying filesystem. If this is not given, then the mount options are either the empty string or "ro" (the latter if the --ro flag is used). By specifying the mount options, you override this default choice. Probably the only time you would use this is to enable ACLs and/or extended attributes if the filesystem can support them:

     -m /dev/sda1:/:acl,user_xattr

    The fourth part of the parameter is the filesystem driver to use, such as "ext3" or "ntfs". This is rarely needed, but can be useful if multiple drivers are valid for a filesystem (eg: "ext2" and "ext3"), or if libguestfs misidentifies a filesystem.

--no-fork
    Don't daemonize (or fork into the background).

-n
--no-sync
    By default, we attempt to sync the guest disk when the FUSE mountpoint is unmounted. If you specify this option, then we don't attempt to sync the disk. See the discussion of autosync in the guestfs(3) manpage.

-o OPTION
--option OPTION
    Pass extra options to FUSE.

    To get a list of all the extra options supported by FUSE, use the command below. Note that only the FUSE -o options can be passed, and only some of them are a good idea.

     guestmount --fuse-help

    Деякі з потенційно корисних параметрів FUSE:

    -o allow_other
        Allow other users to see the filesystem. This option has no effect unless you enable it globally in /etc/fuse.conf.

    -o attr_timeout=N
        Enable attribute caching by FUSE, and set the timeout to N seconds.

    -o kernel_cache
        Allow the kernel to cache files (reduces the number of reads that have to go through the guestfs(3) API). This is generally a good idea if you can afford the extra memory usage.

    -o uid=N -o gid=N
        Use these options to map all UIDs and GIDs inside the guest filesystem to the chosen values.

    -o use_ino
        Preserve inode numbers from the underlying filesystem.

        Without this option, FUSE makes up its own inode numbers. The inode numbers you see in stat(2), "ls -i" etc aren't the inode numbers of the underlying filesystem.

        Note this option is potentially dangerous if the underlying filesystem consists of multiple mountpoints, as you may see duplicate inode numbers appearing through FUSE. Use of this option can confuse some software.

--pid-file НАЗВА_ФАЙЛА
    Write the PID of the guestmount worker process to "filename".

-r
--ro
    Add devices and mount everything read-only. Also disallow writes and make the disk appear read-only to FUSE.

    This is highly recommended if you are not going to edit the guest disk. If the guest is running and this option is not supplied, then there is a strong risk of disk corruption in the guest. We try to prevent this from happening, but it is not always possible.

    Див. також "OPENING DISKS FOR READ AND WRITE" in guestfish(1).

--selinux
    This option is provided for backwards compatibility and does nothing.

-v
--verbose
    Enable verbose messages from underlying libguestfs.

-V
--version
    Display the program version and exit.

-w
--rw
    This changes the -a, -d and -m options so that disks are added and mounts are done read-write.

    Див. "OPENING DISKS FOR READ AND WRITE" in guestfish(1).

-x
--trace
    Trace libguestfs calls and entry into each FUSE function.

    This also stops the daemon from forking into the background (see --no-fork).

ФАЙЛИ

$XDG_CONFIG_HOME/libguestfs/libguestfs-tools.conf
$HOME/.libguestfs-tools.rc
$XDG_CONFIG_DIRS/libguestfs/libguestfs-tools.conf
/etc/libguestfs-tools.conf
    This configuration file controls the default read-only or read-write mode (--ro or --rw).

    Див. libguestfs-tools.conf(5).

СТАН ВИХОДУ
Ця програма повертає значення 0 у разі успішного завершення і ненульове значення, якщо сталася помилка.

ТАКОЖ ПЕРЕГЛЯНЬТЕ
guestunmount(1), fusermount(1), guestfish(1), virt-inspector(1), virt-cat(1), virt-edit(1), virt-tar(1), libguestfs-tools.conf(5), "MOUNT LOCAL" in guestfs(3), http://libguestfs.org/, http://fuse.sf.net/.

АВТОРИ
Richard W.M. Jones ("rjones at redhat dot com")

АВТОРСЬКІ ПРАВА
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.