I have data on tape with a variable block size. when reading these tapes I can use tcopy /dev/st0 (for example) to show the record size as it reads from tape.

Ultimately I copy the data from tape to disk using dd, and this shows me how many records are read in (as well as the final total size), but it would be nice to know the individual record size. Any way of getting this from dd?


Not that I'm aware of. But the option seek might help determine that to some degree. OTOH While I'm not as familiar with it on Linux, mt seems a better (more versatile alternative) for tape related tasks, and apprears to provide what your looking for.



I use mt all the time for operations relating to tape. Things like moving forward, backward, ejecting, etc. But I don't think it reports record sizes (I'll have to double check this). I'm really after something showing record size as this will be a valuable QC tool when reading data from tape. A bonus would doing this during the read so as not to have to read the tape twice.

When copying certain data from tape to disk you lose the valuable information of record and end of file markers, which can cause problems if those are not what they are supposed to be. I'll play around with seek and see if that reports anything. Thanks!

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