How to connect USB Disk (last resort)?

[amitkhas]

So I went ahead and purchased 4x 2TB WD Reds.

My main priority is reliability. Much more so than performance. Trying to recover these 4 failed Hitachi drives has been time-consuming.

You said HDD brands vary. What is considered best in reliability then? Hitachi because of the 10^15 Non-Recoverable Read Error Rate? I suppose it's a moot point since I already made a purchase, but I am curious.

Thanks for the info guys.

 

[solarisguy]

For the last 3 years, what used to be Hitachi drive manufacturing is owned by Western Digital, and is named HGST. For simplicity, I used the name Hitachi :)

Yes, drive brands or drive series that have 1 in 10^15 (Terascale by Seagate, Ultrastar 7K4000 by HGST, WD Re by Western Digital) are designed to be 10 times more reliable, than those for which non-recoverable read errors per bits read is 1 in 10^14.

However, both non-recoverable read errors per bits read and MTFB (or directly derived from it AFR – Annualized Failure Rate) do not give you any guarantee that you would not experience a failure. Such a scenario is just less likely.

What does 1M hours of MTBF mean? Statistically speaking, if you have 6 such drives in 24x7 operation for 20 years, one of them would fail. Good! But, since that is a statistical average, one of other interpretations is as follows: there are 20 FreeNAS users, and each of them deployed 6 such drives in 24x7 operation, then one of the users would have a failed drive within the first year of operation. It could be you (Bad!), it could be one of the other 19 users...