Judging external HD reliability

[Edward Ned Harvey]

> What I care about most is having a hard disk last 5 years under quite
> modest use at home for standard definition video projects.  If I am
> not going for the lowest price, do folks think the "enterprise"
> distinction is worth the extra dollars?  Does it up the odds of the
> device working over long periods of time?
> 
> What do people think about going with a gigabit NAS server for the
> home?
> 
> I have about 500G of videos I may watch a few times at most, and video
> projects that took a few years to use up 500G of space for Final Cut
> Pro projects.  I would like the iPhoto album to be centrally stored.

Buying cheap disks (sata) versus better disks (sas, near-line sas) the cheap
disks definitely fail much more frequently.  It's hard to notice when you
only have one server, but when there are 100's of disks in various machines
in your datacenter, then it's easier to get a feel for it.

Also, each disk is rated to run some number of hours ... Typical for cheap
disks is 25,000 hours (~ 3yrs)

I have an old file server (3 yrs) where a disk just died, and I discovered
the warranty had been neglected, and the model of hard drive required is no
longer for sale, and the failed disk was at 21,000 hours of uptime, and all
the other disks in the system are presently between 20,000 and 22,000.  So
it ain't looking good.

If you want a system to last 5 years, just make sure you pay for the
warranty, and use plenty of redundancy (raidz2 or raid-dp or raid6) plus
hotspare in the system.  That's pretty much the only way to go.

How heavily you use it is basically irrelevant.  Basically the only thing
that matters is number of hours of uptime.