rsync for Mac to copy files around without errors, fast.

If you have to copy a large amount of data, say 15TB from one hard drive to another, the finder is not your friend. The way the finder copies data allows for disk errors or I/O (in/out) errors to fail the whole copy. For example, if you've been running that 15TB copy for a few days and it fails with an error at 99%, you're screwed. Using the terminal to run an rsync command is ideal, it copies files bit by bit, safely, and if there is a problem (disk disconnected? power outage?) run it again and it'll start off where it left off. Sweet. 

Here's How:

• Open the terminal in the utilities folder.
• type in the command: sudo rsync -vaE --progress /Volumes/SourceName /Volumes/DestinationName
  • "/Volumes/SourceName" can simply be added by dragging the source folder to the terminal window and the system will add the path for you. Also, you can add a / to the end of the sourcename to have the contents of the folder copy, rather than the whole folder itself (including contents).
  • "/Volumes/DestinationName" can simply be added by dragging the destination folder to the terminal window and the system will add the path for you. 
• Finally, all the spaces in the command are required, so if you get an error, check the command again. 
• Enter your password when prompted. 

You're welcome. 

*If the copy is interrupted for any reason, run the same command again. 
For advanced rsync commands CLICK HERE
For example commands to exclude files and folder from an rsync copy: CLICK HERE