what your overlooking with respect to the hard drives is that when they fail its catastophic because much more data is lost than an isolated CD/DVD disk or file. If you go with hard drives you would have to use 2 to prevent this like you say. Secondly, if you have a nasty power supply failure or surge issue you CAN destroy all hard drives in the tower that share that power supply/chassis. HDDs are also vulerable to malious viruses, OS bugs, etc. which burned media are not.
Lasty my experience has been different than yours with regards to the optical media. I havent had ANY CD/DVD errors (yet) but I have had several hard drives fail on me over the years but ever since the first one did, I have been OK because I backup everything important on CD/DVD/ZIP/Superdisk all the time. I simply ASSUME the HDDs will fail so if they do I am not screwed. jco -----Original Message----- From: Godfrey DiGiorgi [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 03, 2006 10:39 AM To: [email protected] Subject: Re: archiving workflow (was: DVDs) The key to digital archiving is not media permanence. The key to digital archiving is replication and maintenance. I use twin, paired backup external hard drives as well as CD-R and DVD-R media for backup on important projects. The likelihood that two hard drives will both fail at the same time is infinitesimal; the likelihood that CD/DVD media corruption will happen is greater than that but still small. My workflow schema for digital images runs this way: * Original captures are written to backup #1. * DNG Converter writes reduced size original captures to the working drive. (Scans are simply copied.) * edits happen on the working drive, creating .PSD and .JPEG files. * the working drive is backed up to backup #1, with deletions archived and written to CD/DVD as well. * backup #1 is synchronized to backup #2. - The backup and synchronization copying is performed by automated scripts so it is very consistent and repeatable. - Backup #1 is connected and powered almost all the time, Backup #2 is only connected and powered when being written to. - 30-50% free space is always maintained on the internal (working) drive. - When the backups become full, two new backup drives (typically at double the capacity) are purchased to replace them. Directory catalogs of the old drives are captured, and their contents are mirrored onto the new backup pair. The old drives are then wrapped in antistatic bags and stored as a permanent archive. - Since 1984, I have experienced exactly one hard drive failure. I've experienced a greater number of file corruptions on DVD and CD media (every so often, I do a verification scan of several CDs/DVDs to keep tabs on thos media). For this reason I consider hard drives to be more reliable for long term storage. However, I don't consider either media to be "archival" ... I just keep transitioning the data to newer storage media as appropriate. Prices on hard drive storage drop every year, and quality improves. I've never lost any of my digital photo/image data, the archive/ storage chain is unbroken all the way back to 1983. The sophisticated schema with paired hard drives above was created two-three years ago... I transitioned to CDR+hard drive from floppy+hard drive media in 1995, this schema handles orders of magnitude more data and much more swiftly. My current archive load is approximately 300 added image files per week, far higher than it was a decade ago. Godfrey
