The debugfs manpage gives the impression that the command 'rdump . .' will recursively copy all files found on the specified filesystem from the debugfs cwd to the native filesystem's cwd. Instead I seem to receive a syntax error, and no copy is initiated?

These are the commands I run:

cd /path/to/transfer/destination
debugfs /dev/sda1 -R rdump . .

My task is to copy the entire contents of a clean yet unmountable USB storage device to its host machine's HD. The host machine does not support the inode size used by the USB device's filesystem (256) and its software is not upgradeable, so my intention was to use debugfs to transfer the files. If anyone has any other suggestions for this task I'd be grateful.