Rsync ignore time comparison

Question

What are the flags to make sure rsync ignore modification time and use checksum only?

Answer 1

From the rsync(1) man page:

    -c, --checksum              skip based on checksum, not mod-time & size
       ...
    -I, --ignore-times          don’t skip files that match size and time

As always, -n will help you make sure you have the options you need.