Safepoint

I have a mybooklive 3TB, with almost 2TB used.  I am wanting to perform a safepoint.  My question is how much space on my pc or other device should I expect this safepoint to be?

Thank you to all that contribute regularly.

Hi, the safepoint backup will have the same size of the files that you have saved on the My Book. See page 85 of the manual for more information. 

http://wdc.com/wdproducts/library/UM/ENG/4779-705058.pdf#page=90