On Fri, 17 Mar 2000, Jarkko Hermanni Teppo wrote:

>Hello!
>
>This is probably a stupid question but here goes anyway;
>
>What are the typical values for tape block sizes for tar
>and dump for the following tape drives:
>8mm Exabyte (8200), 1600bpi 9-track, QIC-150, HP 9144 (HCD),
>HP 9145 and DDS-I.
>
>I\'m just looking for some \"canonical\" values...

I believe that for Exabytes you should write 56 KB blocks.
I read somewhere that each pass of the helical-scan head writes a 64 KB
stripe of data, of which 8 KB is CRC, leaving 56 KB for data.
Allegedly, if you write less than 56 KB, the rest of the stripe is unused,
while if you write more than 56 KB, it overflows onto the next stripe,
and the remainder of that is unused.

Roger

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