rsync solutions fails and if the directory is the root of a filesystem you can use the old
dump/restore backup utilities (yes that stills works).
dump duplicates the filesystem characteristics without going through the kernel filesystem interface so it is quite fast.
The inconvenient is that
dump is sensible to modifications made on the source file system while copying.
So better umount the filesystem or remount it read only or stop any application that could access it before starting a copy. If you respect that condition the copy is reliable.
Depending on the filesystem type the
dump command name can change, for instance, you can have the
xfsdump for the XFS.
The following command is similar to the
tar example :
dump 0uf - /dev/sdaX | (cd /target && restore rf -)
The number is the incremental copy level;
0 indicates to do a full copy.