Tape to tape 2: Cooking with smoke now!

Our home-built, cobbled-together-from-scrounged-parts data recovery service has reached a significant milestone. After much wrangling with SCSI cards and bad cables, we finally managed to bring up a Fedora 6 box with two LTO tape drives attached to it. Both drives were high voltage differential SCSI, which meant we needed to dig up an appropriate SCSI card. Managed to find one being sold through Amazon Marketplace and picked it up for $15 with shipping. Card worked fine. Ended up spending several days messing with various combinations of LTO drives and cables before getting something to work.

Now the system is up and running and both drives are recognized by the system. Hoping dd(1) would be all I needed to create a copy of the original tape, I put in
dd if=/dev/st0 of=/dev/st1 bs=256k

10 seconds later, I got a message that a whopping 240 bytes were copied from one tape to the other.

Crap. So much for the simple solution. I'm guessing I'm missing something that's not letting me see the rest of the data on the tape.

But at least it works! The data in that 240 bytes seems to indicate that it's some kind of tape header. Now I just have to figure out how to get to the rest of the data on the tape.