Seagate 3TB HDD's have huge failure rates
Check this report from backup service Backblaze out. They outed a report of their hard drive failure rates, it was done with a very respectable 25,000 hard disk drives. The chart shows a failure rate for all tested HDDs, adn check out the SeaGate 3TB... topping a failure rate of 40%.
Source: Guru3D.com
And most other Seagate HD's too. The most reliable brand currently, based on my personal experience (14 HD's, 1.5 to 3 TB), is Toshiba. I had to RMA most of the Seagate ones within months of purchase, and often lost some pretty valuable data stored on them. Avoid Seagate HD's like the plague.