On 11/16/05, Jim Kuzdrall <[EMAIL PROTECTED]> wrote: > The question is, how do you detect a bad CD batch before losing the > data. Since higher temperature would accelerate the loss of contrast > in the dye, a simple test at high temperature might sort the good > manufacturers or production runs from the bad.
If I can believe everything I read (sarcasm), it is apparently not just the dyes that can cause problems, but poor lamination as well. Supposedly that can lead to mechanical, optical, or chemical (environmental contamination of the recording layer) failures. A big problem with this topic is that it is difficult to tell real info from "I know a guy who said..." stories. And by the time a well-known body of empirical evidence is established, it will be too late. :( FWIW, I back up my own, home systems onto CD-RW. I use multiple discs in rotation, and do a full read-and-compare verify after each backup. If a disc starts to fail, I just toss it. From what I can tell, scratches from my handling are the biggest problem. But I'm not so interested in long-term, offline archives at home. I just backup my archives with my active data. At work, we have way more data then will fit onto a DVD, so we use tapes in a 3-tier rotation (19 regular media sets plus yearly permanent archives). In those quantities, tapes were still way cheaper then HDs when the system was spec'ed out (circa 2000). If I had to spec out something new today, hotswap, removable HDs would definitely be something to consider. I'm a little leary of the idea of carting HDs back and forth all the time, though. Our mortality rates for hard drives with laptops is *much* higher then with desktops, which I see as evidence that handling does make a significant difference. Bearings, spindle motor, media contamination... HDs are a lot more delicate then tapes. So I dunno. Perhaps a hybrid solution as has been discussed. I'm interested in what is going to happen (or maybe already has) with SATA and hotswap. IDE/PATA explictly does *not* support hotswap, or so I've read. So you always have to go with the external enclosure that you can turn on and off to swap disks. SATA is supposed to support hotswap "all the time". That would be nice. -- Ben _______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss
