If data loss is a concern of yours (and it should be) backing up your Mac to hard drive (HDD) is one of the most important things you can do. Although any HDD can fail at anytime, having a clone of your internal HDD to an external HDD lowers the chances by half. The more copies you have on separate devices, the less likely your data will be at risk.
The next step to backing up your mac after you’ve decided it is a good idea is to purchase an external hard drive (EHD). Most EHDs we sell come formatted for a PC, which will not work for your Mac. I can’t count the number of times I’ve sold and EHD to someone who comes into the store the next day stating the backup won’t work. In the next paragraph I will explain how to reformat your EHD so it can work with your mac and more specifically Time Machine.
Turn your Mac on and boot to the desktop. Plug in your EHD and open Disk Utility (in your Applications > Utilities folder). On the left hand side of Disk Utility select your new EHD and then click the Partition tab on the right hand side. Select 1 partition (or more if you desire), then name it in the name field, and select Mac OS Extended (Journaled) for the format. Then click on the Options tab on the bottom and make sure GUID is selected. Once all those settings are complete, click apply. The EHD is now being partitioned and reformatted so that your Mac can read it. After the loading bar in the bottom right is done and the formatting is complete, a Time Machine window may pop up (depending on what OS you have) asking if you would like to use this EHD for a backup device. If this window does not pop up, you would just need to open Time Machine (in System Preferences) and back up manually.
It is important to note that most all new EHDs come preloaded with software for backing up. When you repartition it, Disk Utility will ask you if you want to erase all content on the EHD. Say yes as it is brand new and we don’t need it since your Mac already has Time Machine software built into the OS.
That’s it! Your new EHD is now ready to be used with your Mac.