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dBHEAD
10-25-1999, 02:55 PM
Owing to circumstances beyond my control, I have to archive sessions on 4mm data tape.

The manual discourages this, pointing out that error concealment techniques used in linear storage can cause audible changes to original information. The questions:

1. How bad is this with 4mm tape? Is it cumulative? In other words, if I am continuously archiving the same session when I'm done with it for that day, does it develop more errors over time with each instance of archiving?

2. Is there one kind of 4mm tape which is recommended? I see that there is DDS, DDS2 and DDS3 available. What is the difference?

I'm using Mezzo software, by the way, and a Glyph tape drive.

sheljay
10-25-1999, 04:50 PM
I've been using 4mm for years without too much trouble. Keep the heads clean and use only the 4mm tapes specifically manufactured for archiving. I currently use DDS-3 with Mezzo software. The tapes format to around 12 gigs a piece. They're pricey though - about $23 a tape.

Good luck...

Eric Lambert
10-25-1999, 06:45 PM
The difference between DDS-2 -3, etc. is essentially the speed and capacity of the tape. DDS-3 writes faster and holds more data than DDS-2. I have to put forth my recommendation, though. I've been using a Glyph DDS-2 drive for a few years with little trouble. If you're buying new, though, get DDS-3 or better since it's faster and more current than DDS-2.
As for error accumulation with 4mm I have to say that it does exist. But it's a tape based system and there will always be errors. Just like audio DAT that attempts to error correct poorly written data during playback, DDS-2 or -3 will do the same, trying to work around corrupted numbers.
Having Mezzo is a plus. It's pretty intelligent in it's methods of archiving and I'm confident when I backup and revise sessions that the most current session files will be restored. Even when the computer crashes during a backup/verify/restore Mezzo repairs the tape with acceptable results.