Hi Fellows,
I want to take backup on tape of our server in which informix database is running.

This is the output of our onconfig file:
#TAPEDEV /dev/null # Tape device path
#TAPEDEV 192.168.20.16:/dev/st0 # Tape device path
TAPEDEV C:/DR.dat

Now if I want to take backup on tape then should I un-hash the first two commands or only second command???
Also please share that is there any need to make a file on tape before starting backup as we create file with 660 permissions while taking backup on drive?

Just uncomment the second line.

Assuming /dev/st0 id the tape drive there is no reason to create a file.