Earlier quoted context omitted.
> 15 km/h The tape stores 580TB for a length of 1255m, does that mean the read speed is 580TB/1255m*15km/h = 1.9TB/s ? Seems too high.
Tapes are often structured in bands, and those bands are divided into wraps, and those wraps are divided into tracks. There are many tracks on a tape, and they snake back and forth from end to end on the wrap (so you don't need to "rewind" when you get to the end of the tape—you just start reading back in the other direction). In newer tape drives, you physically can't read all of the data at once because the tape he…
The drive has 32 heads, and reads/writes 32 tracks at a time. It goes from the start of the tape to the end, then aligns with the next 32 tracks and reverses direction.
Each group of 32 tracks is called a wrap. There are 208 wraps, so 6656 total data tracks. Even wraps go one direction, and odd wraps go the other direction.
That's the important part.
But also the tape is divided into 4 "bands", each one holding a quarter of the wraps/tracks. Between the bands, and at the edges of the tape, are special servo tracks that are used for alignment.
So when a source talks about "wraps per band", it's pointless abstraction. Unless you're really in the weeds, the only thing you want to know is the total number of wraps.
