Tape Scanning in Linux

Hi,

Could someone kindly tell me how to scan tapes in Linux. For example,
if there are multiple cpio archives on one tape, how can I find out how
many are on it? If I am thinking correctly, cpio will only list
whatever is the first archive it finds.

Is it in the method of addressing the device? st0 and nst0 etc? or is
there a utility or command that can essentially ls the tape in the
drive?

Thanks much,
Robert