• Charles Kincaid (3/26/2009)


    Disconnected media would have prevented a bunch of the damage that Steve mentioned. How one goes about that can be debated - endlessly.

    Magnetic media, all of it, fades over time. On tape you have the problem of "bleed through" distortion. (Ever watch an old movie on the tube and notice that you can hear the woman scream three seconds before she does? That's because the intense field of the scream in the audio on the tape bleeds onto other layers of tape on the reel.) That is avoided with disk but it fades over time as well. Then disks that are tied to a motor have the problem of frozen bearings if the drive is not started for many years.

    There will be challenges with any media that you pick. You have to know the weak points of each. Anyone that says that the backup media, method, whatever, is perfect is trying to hand you a "stimulus package".

    Here is a proposal. Take 16mm film. Use a LASER on a helical scan to record the data (like the old VTRs did). It is write ONCE. No erase or modification. Modern film stock can sit in reasonable room conditions for over 50 years. You don't change backups once made. Same fire concerns as most other tape like media. Yes, you have to send it out for developing. If this catches on then low cost, on-site processors will become available. (Keep this idea just between us. I'm already consulting my friend. Her name is Pat. Pend.)

    Excuse me if I sound dumb (not quite my subject this) but would you want to keep a backup tape until it bleeds. I would think that when you want to restore a backup from tapethat you would use the newest one and make sure that you replace your old tapes with new ones regularly. I don't know how long these things last but I am sure the people actually using these things knows about that. I am sure that your idea if 16mm film will also work but can't really comment on that. The most important thing is, however you do it, take your backups offline.

    :-PManie Verster
    Developer
    Johannesburg
    South Africa

    I can do all things through Christ who strengthens me. - Holy Bible
    I am a man of fixed and unbending principles, the first of which is to be flexible at all times. - Everett Mckinley Dirkson (Well, I am trying. - Manie Verster)