I'm working on my tape backup program, and I have several tape devices listed in /dev. I know that the nst are non-rewinding versions of st, but I can't find an explanation (that I can understand) on the suffixes. There is st0, st0a, st0l, and st0m. There are 4 modes, and the suffixes are indicators of the tape mode.
What I don't understand is what "mode" means. I've been through some of the tape documentation that I've found, but it seems to be used in more than one context, and so far haven't found anything that says 0 = X, a = Y, etc.
Can anybody help?