On Mon, 17 Oct 2005 21:18:24 -0700, Father Kodak
wrote:

On 17 Oct 2005 19:51:06 -0700, "mp" wrote:

If anything, get a USB RAID storage device to store the images.
(Sometimes called a SAN)

The only problem with USB (and I currently have 5 external USB drives
running) is transferring large amounts of data is slow compared to
internal drives. However with individual files and directories up to
a gig or so you'd never notice the difference. Back up a 300 Gig
drive and you do notice the difference. Make sure to have the drives
on different controllers too. If they are both on the same
controller they will get *really* slow.


Or, get some really big drives for one of my systems. Probably a SATA
RAID.

Two of the systems here use 400 Gig SATA RAIDs.



If you want to justify a new PC, then get one with a RAID that is set
to mirror. I'd advise the external RAID anyway.

Nothing worse than losing a drive with most of your images on it.

Just remember that data integrity is normally compromised by the user
far more often than by hardware.

I now have RAIDs in two of the machines, but went to striping and use
external USB drives as back up. With 4 machines I can copy the back up
drive and have far more storage for the dollar. That is on a system
now approaching 4 terabytes.

If you trash a file on your RAID the chances are you have also trashed
the mirror image. Even if it's an interruption while writing you will
normally get them both.

You can get very expensive RAIDS that will not trash due to hard ware
problems, but they still can do nothing for the user problem.

As for USB RAIDs they don't make sense to me as there is no need for
mirroring on an external drive if you already have another drive with
the same images. That and the external drives are slower so you gain
nothing by striping.

Mirroring a backup drive does nothing, or very little for your data
integrity. Duplicating a backup drive does a lot.

I have the files on one machine and they are backed up across a
gigabit network to an external drive on another machine in a different
building.



Agreed. Or losing anything else. For years I've been doing backups
to tape with good results. I have never used low-end DDS, so I
haven't experienced the problems that people have been having with
that technology.

As I've said before, the (multinational) corporation where I worked
only used tape drives for short term and these were high end drives.
We even had a robot running up and down the aisle selecting tapes.
OTOH We were moving to all optical, system by system.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com