Every so often, I'll run the following command to quickly see which amanda tape 
is currently in my tape drive:

# dd if=/dev/nst0 bs=32k

Most of the time, I'll get the header information, but every so often I have to 
run the command twice for the system to successfully read the tape.  i.e.:

bash$ dd if=/dev/tape bs=32k
0+0 records in
0+0 records out

bash$ dd if=/dev/tape bs=32k
AMANDA: TAPESTART DATE 20180319 TAPE SIMNET-02

1+0 records in
1+0 records out


Any idea why this happens?

-Rob