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Double density in tapes.

Manuales
Super Advisor

Double density in tapes.

Hi ..
i'm making some backup's ...
1.- can you tell me what is the meanning of 2 density ?
2.- is a kind of special tape?
3.- what is the meanning of double density ?

Thanks, Manuales.
5 REPLIES
A. Clay Stephenson
Acclaimed Contributor

Re: Double density in tapes.

These terms differ in meaning with the kind of tape technology (9-track, DDS, DLT, ...)

In same cases, it means a different tape and it others it means a different recording format using the same tape.

What kind of tape technology are you using?
If it ain't broke, I can fix that.
Manuales
Super Advisor

Re: Double density in tapes.

We are using DDS tapes.
but, i can't understand what is double density.. is a tape with more density or are 2 tapes?

thanks, Manuales.
A. Clay Stephenson
Acclaimed Contributor

Re: Double density in tapes.

Now, Is your tape drive DDS, DDS2, DDS3, or DDS4. This can range in capacity from 1GB to 24GB (compressed). The higher DDS levels can read the lower versions but the lower versions cannot read the higher versions.

Double density normally means physically writing at 2 times the "normal" recording density. This is typically achieved by writing more but narrower tracks. This is not the same as compression. It never means using 2 tapes.
If it ain't broke, I can fix that.
Manuales
Super Advisor

Re: Double density in tapes.

We are using DDS ..
operating system is 10.20 y 11.0
can i use a tape of double density?

Thanks, Manuales.
Marino Meloni_1
Honored Contributor

Re: Double density in tapes.

http://www.mvps.org/PracticallyNerded/Glossary/Gloss_D.htm

tapes drives do not use the term double density.

usualy we use a Native capacity vs a commercial capacity for example:
DDS4 is also called dat 20/40 of DAT40, in fact the native capacity is 20 GByte, but as he have a data compressor build in the Hardware, you may store more data, and it is usualy called DAT40 because it allow to store 40 GByte data if you data allow a compression ration 2:1.
So, more compressible are the data, more data you can store on your DDS drive.