When you buy a hard drive, you need to know what the purpose is for. For backup, you may consider an external drive, NAS or even disk array. After defining the purpose, you need to consider the hard drive interface. You need a SATA 600; SATA 300; SAS; USB 2.0 or Firewire 800. Hard drive capacity and RPM are important, the higher RPM, the better transfer rate and will be more expensive. There is also a new breed of hard drive available in the market, namely the SSD and Hybrid Hard Drive. Vuugo has over 200 hard drive models for you to choose. We carry major brands like Seagate, Western Digital, Lenovo, Iomega, Tandberg, Samsung, G-Tech, Toshiba and more.