If the drives are in a RAID configuration, then yes, they can be
used.  But to treat the portable drives like an archive (ie. 
optical/tape), you'll want to have multiple copies on separate
drives in separate locations.  Even then, my biggest concern with
these drives is that their life is unpredictable.

I have a few TB of portable drives, and have yet to lose one
(knock on wood).  But temperature and relative humidity are 
controlled, and they get used regularly.  And so I sleep at night, 
I roll the data off to optical.  I'm looking at stepping up to
tape backup - I think I've hit the quantity where tape is going
to be cheaper (looking at an AIT library, software TBD).

If you want to use portables, my favorite combination is to 
purchase a bare Hitachi hard drive and load it into a USB2 
case.  Not only is this more cost effective than buying
pre-packaged drives, but the Hitachi reliability is well known.
I've had good luck with recent Western Digital drives so far 
(I've heard others with their earlier drives experience 
premature failures).  I also have one Seagate in the mix (I
couldn't resist the rebate).  I won't touch any other drive

I'd be curious to hear how other small archives and studios
deal with their storage (RAID, optical library, tape library,
software to manage archives, etc.).

Eric Jacobs
The Audio Archive

---- Original message ----
>Date: Thu, 8 Sep 2005 09:22:37 -0400
>From: "Richard L. Hess" <[log in to unmask]>  
>Great advice, Eric, but just to clarify, with proper strategy there 
>is nothing wrong with using multiple external/portable hard disks. 
>I'm not a proponent of just putting them on the shelf, however.