raw disk copying?

Tom Uban wrote: I think that you are making this far more complicated than it is. Linux has two types of devices - block and character. Obviously block devices communicate in fixed sized chunks while character devices are everything else. You can do anything you want to a hard disk using the /dev/hd* or /dev/sd* block devices. When you access a hard disk in this way, there is no filesystem interpretation or data structure interpretation at all. It's just plain raw data. It might be buffered at some level, but it is certainly not interpreted in any way. Older Unix's may have allowed you to use a character interface to speak to a hard disk to avoid buffering. Remember, Linux isn't technically Unix. It is Unix-like. Go read the list of devices .. there is no character mode access to block devices, unless you write your own device driver to do it. The standard set of major and minor numbers always have hard disks as block devices - nothing else. The issue of how to handle read errors is different .. dd isn't very graceful about error handling. I would suspect that after a retry or two it should clear up. I'm not sure if the kernel or the hardware automatically retry for you, and at what point they give up. Mike