macosusb-driveusb-flash-drive

Most efficient way to copy data to multiple USB drives in OS X

I have a need to duplicate about 10 USB thumb drives a day from a Dropbox folder that changes slightly each day (about 10GB of data). I considered the $300 "Aleratec 1:10 USB 3.0 Copy Cruiser" but upon study, realized it's no more than a USB 3.0 hub and some basic copying software. I can do this with my own USB 3.0 hub and Terminal in OS X! (Windows 10 is also available if there's an easier way.)

Question: Since the bus is faster than my drives, is there a way I can execute this command to write to all the drives simultaneously? Or any other creative suggestions appreciated. Thanks.

Solution

  • You can format them in parallel quite easily, if you make a little script. Say your drives have the word USB in their names, you could write something like this:

    #!/bin/bash

# Don't barf if no drives mounted, or if USB is lowercase
shopt -s nullglob
shopt -s nocaseglob

# Iterate through all mounted USB drives
for drive in /Volumes/*USB* ; do

   # rsync source to USB drive in background
   echo rsync <options> <YOURSOURCE> "$drive" &

done

# wait for all parallel rsyncs to finish
wait

    You would save that on your Desktop, as DuplicateUSB and then you make it executable like this in Terminal:

    chmod +x "$HOME/Desktop/DuplicateUSB"

    Then you can run it by double-clicking it, or going in Terminal and typing:

    $HOME/Desktop/DuplicateUSB

    At the moment, it only echoes what it would do, but doesn't actually do anything. When it looks to be correct, and you are happy with what it is doing, you can remove the word echo from the line with rsync in it so it actually does the rsync.