I have a 10MB input file and a 30GB output file that I need to produce. What I am looking for is a way to instruct the dd program to continue reading the 10MB file as many times as needed to produce the 30GB output file. Example:
dd ifile=/root/input_file ofile=/root/output_file bs=1M count=30720
Currently if I try to do this, dd will stop once the end of the input file is reached, so the output file is the same size as (and identical to) the input file. I can't do any tricks like using piping of multiple commands, as I need to measure the time it takes for this single dd call to complete.
I've looked through man pages and have searched around and I haven't been able to find anything that would suggest that this is possible, so this is my last resort. Does anyone have any idea as to how this could be done? (Ideally, the solution is to use a command-line argument available in dd to get me this functionality, but I haven't seen such an ability). Thanks!