To avoid copying more files than you really need to, when copying to external disks:
- DST - ignore daylight saving time differences
- FFT - ignore 2 second differences (that can occur when using fat)
- XO - ignore files older in source
Other very useful options
- TS - display timestamp for each source file
- L - list only
- R:3 - only retry three times, not a million
Current line:
robocopy <source> <destination> /fft /dst /ts /dst /r:3 /s