Can I read a dd created tape?

Corinna Vinschen
Wed Mar 31 19:45:00 GMT 1999

Bajusz, Richard G. wrote:
> I've got a series of tapes created on a Sun with the dd command that I have
> to read on an
> NT workstation.  The current solution is to boot into Linux, read the tape
> to a FAT partition, and reboot into NT to process the data.  There must be a
> better way!
> Is there a version of dd (or something similar) for NT?

Try using the  patched version of b20.1, supporting raw access to partitions,
hard drives and tapes on


I have noticed an error in it, yesterday, which prevent usage of raw devices
as stdin, but usage as parameter as in

	dd if=/dev/st0 ...

is possible. The error will be corrected in one of the next winsup-snapshots.

Note, that the blocking factor is a _very_ important setting, because windows
sets default blocking of 512 bytes on raw devices. If your SUN writes with 5120
bytes blocking, you'll have to set the correct blocking factor, too, if your
tape drive has variable blocking factors. Try usage of the following commands
from the forementioned web page:

mt:	mt-1.8.README
	mt-1.8.tar.gz	(very useful! Setting of blocking factor as with linux mt)

cpio:	cpio-2.4.2.README

tar:	tar-1.12.tape_cygwin1.README

The dd from cygwin package is ok.

Hope, this helps,

Want to unsubscribe from this list?
Send a message to

More information about the Cygwin mailing list