Backup an entire hard disk using dd command
The ‘ dd ‘ command is one of the original Unix utilities and should be in everyone’s tool box. It can strip headers, extract parts of binary files and write into the middle of floppy disks; it is used by the Linux kernel Makefiles to make boot images. It can be used to copy and convert magnetic tape formats, convert between ASCII and EBCDIC, swap bytes, and force to upper and lowercase.
1 | dd --help |
For more options check dd man page
Using dd you can create backups of an entire harddisk or just a parts of it. This is also usefull to quickly copy installations to similar machines. It will only work on disks that are exactly the same in disk geometry, meaning they have to the same model from the same brand.
Full hard disk copy
1 2 3 | dd if=/dev/hdx of=/dev/hdy dd if=/dev/hdx of=/path/to/image dd if=/dev/hdx | gzip > /path/to/image.gz |
hdx could be hda, hdb etc. In the second example gzip is used to compress the image if it is really just a backup.
Restore Backup of hard disk copy
1 2 | dd if=/path/to/image of=/dev/hdx gzip -dc /path/to/image.gz | dd of=/dev/hdx |
MBR backup
In order to backup only the first few bytes containing the MBR and the partition table you can use dd as well.
1 | dd if=/dev/hdx of=/path/to/image count=1 bs=512 |
MBR restore
1 | dd if=/path/to/image of=/dev/hdx |
Add “count=1 bs=446″ to exclude the partition table from being written to disk. You can manually restore the table.
[via DebianHelp]
