Introduction
This article is dedicated to documenting methods of performing drive imaging (also called bare metal backups, or disk cloning). Drive imaging is a complete copy of all information on a drive, necessary to restore all of the data or entire operating system on a drive to the same state it was when the image was created. This is different from imaging a partition, where one is making a copy of an individual partition that resides on a drive, or backing up individual files and folders.
Please ensure you are comfortable with the information discussed before proceeding. Improperly executing a command may result in partial or complete data loss. Please double- or even triple-check your target device to avoid such catastrophic loss.
Preparations
- Exclusive access to the drive being imaged (i.e. the drive being imaged shouldn’t be mounted). Live operating system imaging methods, for example, physical-to-virtual (P2V), virtual-to-virtual (V2V), etc. are not covered here.
- The location (remote file share, external USB drive, internal drive, etc.) where the drive image is being backed up to should have the same or more free space then that of the drive being imaging. For example, if you are imaging a 160GB drive, you should have 160GB or more free space to back up to.
- The filesystem of the backup location needs to support the filesize necessary to backup the image as one file.
- An environment to perform the drive imaging. This can be a live environment where one images the data of the computers internal drive.
dd is a universal command line program used for low level copying of data. It will copy the entire drive, even if the used data is only consuming 10% of the beginning of the drive. For example, dd’ing a 100GB drive, where all the data is at the beginning, and is only 10GB is being consumed, the resulting file will be 100GB in size.
In order to find out which drive to clone, open a terminal and execute:
The output of the command will list each hard drive (ex. /dev/sda).
Backup with dd
The following example will create a drive image of /dev/sda, the image will be backed up to an external drive, and compressed. For example, one may use bzip2 for maximum compression:
sudo dd if=/dev/sda | bzip2 > /media/usb/image.bz2
However, one may use this same concept to change the compression type (gzip, zip, etc.) to one that best suites your needs (higher compression speed, preferred compression format, etc.).
Restoring a drive image
To restore a drive image, one will want to boot into a live environment. Restoration is quite simple, and really just involves reversing the if and of values. This will tell dd to overwrite the drive with the data that is stored in the file. Ensure the image file isn’t stored on the drive you’re restoring to. If you do this, eventually during the operation dd will overwrite the image file, corrupting it and your drive.
To restore the drive above:
bzcat /media/usb/image.bz2 | dd of=/dev/sda
When restoring the whole drive, the system will not automatically create the devices (/dev/sda1, /dev/sda2, etc.). Reboot to ensure automatic detection.
If you restored Ubuntu to a new drive, and the UUIDs (see UsingUUID for more) changed, then you must change the bootloader and the mount points. One will want to edit the following via a terminal:
sudo nano /boot/grub/menu.lst sudo nano /etc/fstab
To know what the new UUIDs for your drives are, use the following command:
From this list, you can cross-reference the information with that of fdisk to know which drive is which. Then simply update the UUIDs in both GRUB and fstab files.
Clone Drive
Clone the contents of a whole hard drive onto another completely different drive
Clonezilla
https://launchpad.net/ubuntu/+source/clonezilla is another modern imaging solution. For more on it, please see the Clonezilla homepage.
DriveImaging (последним исправлял пользователь qiii 2015-09-28 17:55:23)
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Disk cloning
Disk cloning is the process of making an image of a partition or of an entire hard drive. This can be useful for copying the drive to other computers or for backup and recovery purposes.
- Moving to a drive with a smaller logical sector size (e.g. from 4096 bytes to 512 bytes) will require recreating the partition table since partition boundaries are specified in sector numbers.
- Moving to a drive with a larger logical sector size (e.g. from 512 bytes to 4096 bytes) may not be possible at all if a file system’s block size is less than target drive’s logical sector size or is not divisible by it.
Tip: Over time file systems get new features and the mkfs utilities change their defaults, but not all new features can be enabled without reformatting. So, when moving data to a new drive, instead of cloning the block devices or file systems, consider creating a new file system and only copy the files (and their attributes, ACLs, extended attributes, etc.) with e.g. rsync.
Block-level cloning
Using dd
Using ddrescue
If possible, data recovery from disks should be performed using their native interface: SATA or, for older drives, IDE. Results may vary while using USB adapters.
GNU ddrescue is a data recovery tool capable of ignoring read errors. ddrescue is not related to dd in any way except that both can be used for copying data from one device to another. The key difference is that ddrescue uses a sophisticated algorithm to copy data from failing drives causing them as little additional damage as possible. See the ddrescue manual for details.
To clone a faulty or dying drive, run ddrescue twice. For the first round, copy every block without read error and map the errors to rescue.map .
# ddrescue --force -n /dev/sdX /dev/sdY rescue.map
where X is the partition letter of the source and Y of the target block device.
For the second round, copy only the bad blocks and try 3 times to read from the source before giving up.
# ddrescue --force -d -r3 -n /dev/sdX /dev/sdY rescue.map
In some circumstances the disk controller or a USB adapter may lock, while attempting to read a particular sector. The -i option may be used to instruct ddrescue to start reading after that position.
Now you can check the file system for corruption and mount the new drive.
File system cloning
This article or section needs expansion.
Using e2image
e2image is a tool included in e2fsprogs for debugging purposes. It can be used to copy ext2, ext3, and ext4 partitions efficiently by only copying the used blocks. Note that this only works for ext2, ext3, and ext4 filesystems, and the unused blocks are not copied so this may not be a useful tool if one is hoping to recover deleted files.
To clone a partition from physical disk /dev/sda , partition 1, to physical disk /dev/sdb , partition 1 with e2image, run
# e2image -ra -p /dev/sda1 /dev/sdb1
Versatile cloning solutions
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Reason: This application list does not respect Template:App#Style and might be better as a table. (Discuss in Talk:Disk cloning)
These applications allow easy backup of entire filesystems and recovery in case of failure, usually in the form of a Live CD or USB drive. They contain complete system images from one or more specific points in time and are frequently used to record known good configurations. See Wikipedia:Comparison of disk cloning software for their comparison.
See also Synchronization and backup programs for other applications that can take full system snapshots, among other functionality.
- Clonezilla — A partition and disk imaging/cloning program which helps with system deployment, bare metal backup and recovery.
- Complete backup and recovery solution: able to image and restore entire drives including boot sector, bootloader, partition table. for different operating systems including Windows
- Supports BIOS and UEFI, MBR and GPT
- Supports most filesystems (ext2-3-4, reiserfs, reiser4, xfs, jfs, btrfs, f2fs, FAT12-16-32, NTFS, HFS+, UFS and others) and LVM2
- Free-space aware when using Partclone (default), Partimage (optional), ntfsclone (optional), otherwise falls back to dd for block-level copying (dm-crypt/LUKS containers, unsupported filesystems. )
- Supports multi-threaded compression with different formats (including zstd) and levels
- Supports encrypting the backup
- Multicasting server to restore to many machines at once
- Dedicated LiveCD available to boot from CD, USB drive or PXE server
- Included on the Arch Linux installation media.
- Deepin Clone — Tool by Deepin to backup and restore. It supports to clone, backup and restore disk or partition.
- FSArchiver — A safe and flexible file-system backup/deployment tool
- Support for basic and extended file attributes
- Support for basic file-system attributes (label, uuid, block-size) for all linux file-systems
- Support for multiple file-systems per archive
- Support for all major Linux filesystems (extfs, xfs, btrfs, reiserfs, etc) and FAT (in order to backup/restore EFI System Partitions)
- Experimental support for cloning ntfs filesystems
- Checksumming of everything which is written in the archive (headers, data blocks, whole files)
- Ability to restore an archive which is corrupt (it will just skip the current file)
- Multi-threaded lzo, lz4, gzip, bzip2, xz/lzma and zstd compression
- Support for splitting large archives into several files with a fixed maximum size
- Encryption of the archive using a password. Based on blowfish from libgcrypt
- Support for restoring to a bigger or smaller partition (as long as there is enough space to store the data)
- Support for exclusion patterns to filter what is archived/restored
- Works with directories (creating a compressed and checksummed tarball of sorts)
- Included on the Arch Linux installation media
- Mondo Rescue — A disaster recovery solution to create backup media that can be used to redeploy the damaged system.
- Image-based backups, supporting Linux/Windows.
- Compression rate is adjustable.
- Can backup live systems (without having to halt it).
- Can split image over many files.
- Supports booting to a Live CD to perform a full restore.
- Can backup/restore over NFS, from CDs, tape drives and other media.
- Can verify backups.
- Partclone — A tool that can be used to back up and restore a partition while considering only used blocks.
- Supports ext2, ext3, ext4, hfs+, reiserfs, reiser4, btrfs, vmfs3, vmfs5, xfs, jfs, ufs, ntfs, fat(12/16/32), exfat, f2fs, nilfs
- Supports pipe, stdin and stdout to script special features (compression, encryption. )
- Rescue mode tries to skip bad blocks and backup only good blocks, option to create GNU Ddrescue domain log file from source device
- ncurses interface available
- All backed-up blocks are checksummed with crc32
- Included on the Arch Linux installation media
- Partimage — An ncurses disk cloning utility for Linux/UNIX environments.
- Has a Live CD.
- Supports the most popular filesystems on Linux, Windows and Mac OS.
- Compression.
- Saving to multiple CDs or DVDs or across a network using Samba/NFS.
- Development stopped in favor of FSArchiver.
- Redo Backup and Recovery — A backup and disaster recovery application that runs from a bootable Linux CD image.
- Is capable of bare-metal backup and recovery of disk partitions.
- Uses xPUD and Partclone for the backend.
- System Tar & Restore — Backup and Restore your system using tar or Transfer it with rsync
- GUI and CLI interfaces
- Creates .tar.gz, .tar.bz2, .tar.xz or .tar archives
- Supports openssl / gpg encryption
- Uses rsync to transfer a running system
- Supports Grub2, Syslinux, EFISTUB/efibootmgr and Systemd/bootctl
See also