EX HD or Backup

I wanted people opinions on how to proceed with backing up media. Do you just store it on an external HD along with placing the file on the EX4. OR do you just use the external hard drive as a back up for the folder you place the file in on the EX4. 

Hope its not to confusing. Was just trying to sort out backup and keeping the data I put on the EX4 safe. 

Hello,

You can backup the data you have on the EX4 to a external hard drive,

Take a look at page # 53 of the EX4 User’s Manual.

http://www.wdc.com/wdproducts/library/UM/ENG/4779-705113.pdf