This only works with IBM-branded LTO-5 or newer tape drives, although there is
a file backend for simulation purposes.

You will only be able to read and write tapes with a blocksize <= MAXPHYS,
which is 128KB by default. Put the following in your kernel config file and
recompile/reinstall to allow reading and writing tapes up to the maximum LTFS
blocksize of 1MB:

options MAXPHYS=(1024*1056)