man pages section 1M: System Administration Commands

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Updated: July 2014
 
 

ntfsclone(1M)

Name

ntfsclone - clone, image, restore, or rescue an NTFS

Synopsis

ntfsclone [options] source
ntfsclone --save-image [options] source
ntfsclone --resotore-image [options] source
ntfsclone --metadata [options] source

Description

The ntfsclone utility efficiently clones (which includes copy, save, backup, and restore operations) or rescues an NTFS filesystem to a sparse file, an image, a device (partition), or to standard output. It works at disk sector level and copies only the written data (that is, not empty space). Unused disk space becomes zero (cloning to sparse file), encoded with control codes (saving in special image format), left unchanged (cloning to a disk/partition) or filled with zeros (cloning to standard output).

ntfsclone can be useful in making backups—taking an exact snapshot of an NTFS filesystem—and restoring it later on. It also can be used to test NTFS read/write functionality and allows you to troubleshoot users' issues using the clone, without the risk of destroying the original file system.

If not using the special image format (see section of the same name below), the clone is an exact copy of the original NTFS file system, from sector to sector. Thus, it can also be mounted just like the original NTFS filesystem. For example, if you clone to a file and the kernel has a loopback device and NTFS support, then the file can be mounted using:

# mount -t ntfs -o loop ntfsclone.img

Windows Cloning

You must exercise great care to copy, move or restore a system or boot partition to another computer, or to a different disk or partition (for example, /dev/dsk/c0d0p1 to /dev/dsk/c0d0p2, /dev/dsk/c0d0p1 to /dev/dsk/c0d1p1 or to a different disk sector offset).

Under most circumstances, to enable Windows to boot you must copy, move, or restore NTFS to the same partition that has the following characteristics as the original partition and disk:

  • starts at the same sector

  • on the same type of disk

  • having the same BIOS legacy cylinder setting

The ntfsclone utility guarantees an exact copy of NTFS but does not deal with booting issues. This is by design: ntfsclone is a file system, not a system, utility. Its goal is only NTFS cloning, not Windows cloning. Because of this, ntfsclone can be used as a very fast and reliable building block for Windows cloning, but is not a complete answer.

Sparse Files

A file containing unallocated blocks (holes) is referred to as a “sparse file”. The reported size of such files is always higher than the disk space consumed by them. The du(1) command reports the real disk space used by a sparse file. The holes are always read as zeros. All major Linux file systems, such as, ext2, ext3, reiserfs, Reiser4, JFS, and XFS support sparse files. However, the ISO 9600 CD-ROM file system, as one example, does not.

Special Image Format

It is recommended that you save an NTFS filesystem to a special image format. Instead of representing unallocated blocks as holes, they are encoded using control codes. Thus, the image saves space without requiring sparse file support. The image format is ideal for streaming file system images over the network. The disadvantage of the special image format is that you cannot mount the image directly; you must first restore it.

To save an image using the special image format, use the –s or the –-save-image option. To restore an image, use the –r or the –-restore-image option. Note that you can restore images from standard input by using a hyphen (-) as the source file.

Metadata-only Cloning

Using the –m or ––metadata option, ntfsclone can save only the NTFS metadata and the clone still will be mountable. In this usage, all non-metadata file content is lost; reading back the data results in all zeros.

The metadata-only image can be compressed very well, usually to a size in the range of 1 to 8 MB. It is convenient to transfer such an image for investigation and troubleshooting.

In metadata-only mode, ntfsclone saves none of the user's data, which includes the resident user's data embedded into metadata. All is filled with zeros. Moreover, all the file timestamps, and deleted and unused spaces inside the metadata are filled with zeros. Thus, this mode is inappropriate, for example, for forensic analyses.

Note that filenames are not removed. Because a filename might contain sensitive information, consider the possibities for breaches of security or privacy before sending out a metadata-only image.

Options

Supported options are listed below. Most options have both single-letter and full-name forms. Multiple single-letter options that do not take an argument can be combined. For example, –fv is the equivalent of –f –v. A full-name option can be abbreviated to a unique prefix of its name.

–f, ––force

Forces ntfsclone to proceed, even if the filesystem is marked “dirty” following a consistency check.

–h, ––help

Show a list of options with a brief description of each one.

–i, ––ignore-fs-check

Ignore the result of the file system consistency check. This option can be used only with the –-meta-data option. Any clusters that cause an inconsistency are saved.

–m, ––metadata

Clone only metadata. With this option, you must clone only to a file.

–o, ––output file

Clone NTFS to the non-existent file. If file is a hyphen (-), clone to the standard output.

–O, ––overwrite file

Clone NTFS to file, overwriting file if it already exists.

––rescue

Ignore disk read errors so that a disk having bad sectors, for example, a failing disk, can be rescued with minimal impact on the disk. ntfsclone works at the lowest, sector level in this mode, enabling more data to be rescued. The contents of the unreadable sectors are filled with the question mark (?) character; the beginning of such sectors are marked by the string: BadSector.

–r, ––restore-image source

Restore from the special image format specified by source. If source is a hyphen (-), the image is read from the standard input.

–s, ––save-image

Save to the special image format. In terms of space usage and speed, this is the most efficient option if imaging is done to the standard output. This option is useful for image compression, encryption, or streaming through a network.

Examples

Example 1 Cloning with Overwrite Option

The following command clones with the ––overwrite option.

# ntfsclone --overwrite /dev/dsk/c0d2p1 /dev/dsk/c0d0p1
Example 2 Saving to Special Image Format

The following command clones to the special image format to its original partition.

# ntfsclone --save-image --output backup.img /dev/dsk/c0d0p1
Example 3 Restoring from a Special Image File

The following command restores an NTFS from a special image file.

# ntfsclone --restore-image --overwrite /dev/dsk/c0d0p1 backup.img
Example 4 Saving to a Compressed Image

The following command saves an NTFS to a compressed image file.

# ntfsclone --save-image -o - /dev/dsk/c0d0p1
Example 5 Restoring from a Compressed Image

The following command restores an NTFS volume from a compressed image file.

# gunzip -c backup.img.gz | \
ntfsclone --restore-image --overwrite /dev/dsk/c0d0p1 -
Example 6 Backing up to a Remote Host Using ssh

The following command backs up to a remote host, using ssh(1). Note that ssh will probably require a password.

# ntfsclone --save-image --output - /dev/dsk/c0d0p1 | \
gzip -c | ssh host `cat > backup.img.gz`
Example 7 Restoring from a Remote Host Using ssh

The following command restores from a remote host, using ssh(1). Note that ssh will probably require a password.

# ssh host `cat backup.img.gz` | gunzip -c  | \
ntfsclone --restore-image --overwrite /dev/dsk/c0d0p1 -
Example 8 Streaming an Image File from a Web Server

The following command streams an image file from a web server and restore it to a partition.

# wget -qO - http://server/backup.img | \
ntfsclone --restore-image --overwrite /dev/dsk/c0d0p1 -
Example 9 Cloning to a New File

The following command clones an NTFS volume to a non-existent file.

# ntfsclone --output ntfs-clone.img /dev/dsk/c0d0p1
Example 10 Packing NTFS Metadata

The following command packs NTFS metadata into an image file. Note that bzip2 takes a much longer time than gzip, but produces an archive that is up to ten times smaller than the latter produces.

# ntfsclone --metadata --output ntfsmeta.img /dev/dsk/c0d0p1
bzip2 ntfsmeta.img
Example 11 Unpacking NTFS Metadata

The following command unpacks NTFS metadata into a sparse file.

# bunzip2 -c ntfsmeta.img.bz2 | \
cp --sparse=always /proc/self/fd/0 ntfsmeta.img

Exit Status

The return code is zero on success, non-zero otherwise.

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Availability
system/file-system/ntfsprogs
Interface Stability
Uncommitted

See also

du(1), ssh(1), ntfsresize(1M), ntfsundelete(1M), parted(1M), attributes(5)

Authors

Authors

ntfsclone was written by Szabolcs Szakacsits with contributions from Per Olofsson (special image format support) and Anton Altaparmakov.