clone2fs is an utility to clone an ext2/ext3 filesystem. Unlike dd, clone2fs does not copy the whole volume but only blocks that are actually in use. Therefore, it is usually faster. It's also faster than dump/restore, tar or similar backup software because it accesses the source and destination volumes sequentially most of the time.

Note that clone2fs allows you to clone a mounted file system without warning, even if it's writable. In the latter case, you have to run e2fsck on the resulting image in order to make it consistent. Since copying takes a while, changes made while clone2fs is working may or may not appear in the clone. If you need an exact clone, umount the source file system, or remount it in read-only mode.