Judging external HD reliability

[richb-RBmg6HWzfGThzJAekONQAQ at public.gmane.org (Luis Fernández & Rich Braun)]

Doug <dougsweetser-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org> wrote:
>  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?

For work I get the 2.5" 15Krpm enterprise drives, 72GB or 146GB.  They cost a
bundle, like $300+ apiece.

For home I get Seagate Momentus 2.5" drives on my desktop (much lower power
than 3.5") and run 4 of them as RAID10 (in case I want to do video editing). 
For the server I've most recently gotten the Seagate 2TB 5900rpm drives (at
Microcenter for about $170ea, less by mail-order).  With the latter you could
build a NAS server with software RAID5 for just under $1000, 6TB to 8TB of
capacity.

When cramming a server full of drives don't try to go cheap on the power
supply.  I'm on the third PS for my server, finally opting for a $100 one
instead of the lesser ones.  Look for the 80% efficiency label (in this era of
green-this/green-that I'm still flummoxed that computer power supplies of
under 70% efficiency remain the norm, and the high-efficiency ones cost so
much more that it'll take 5 years+ to accomplish any cost savings).

Implicit in your NAS question is whether to buy a prepackaged one or build
your own.  I always build my own just because I want to be able to swap out
drives and change the configurations.  Software RAID is not only cheaper but
much more flexible.  In RAID1 or RAID10 mirror configs, it's just as fast as
any hardware.  My favorite hardware controller for RAID5 is the Dell PERC6.

Individual hard drives tend to fail either soon after purchase or sometime
between 3 and 10 years later.  Ever since drives dropped below $200, I've
/always/ used RAID because of the sheer inconvenience of restoring from
backups.  RAID is truly free because you can just keep one of your old drives
to use as a mirror.

-rich