Whether you’re trying to rescue data from a dying storage drive, backing up archives to remote storage, or making a perfect copy of an active partition somewhere else, you’ll need to know how to safely and reliably copy drives and filesystems. Fortunately,
dd is a simple and powerful image-copying tool that’s been around, well, pretty much forever. And in all that time, nothing’s come along that does the job better.
dd, on the other hand, can make perfect byte-for-byte images of, well, just about anything digital. But before you start flinging partitions from one end of the earth to the other, I should mention that there’s some truth to that old Unix admin joke: “dd stands for disk destroyer.” If you type even one wrong character in a
dd command, you can instantly and permanently wipe out an entire drive of valuable data. And yes, spelling counts.
Remember: Before pressing that Enter key to invoke
dd, pause and think very carefully!
Read more at OpenSource.com