Long term (offline) storage of data.

[MARREEL Chris_1]

I was wondering, what medium could be considered as a good medium for a long term (offline) storage of data ?

For us, long term is 10 - 15 years.

I'm using DDS as a backup medium now, and I use this (at the moment) for long term storage, but as far as I know magnetisme is used to put the data on the tape. Will this information last for 10 - 15 years on the tape ?
Will we be abel to buy a DDS-tape-reader in 10 - 15 years ?

Share your knowledge..

Thanks,
Chris MARREEL

[Ron Kinner]

Turns out it's not so much the magnetism which wears out but the glue which holds the material to the tape. Lifespan also depends a lot on the quality of your archive tape. Regular backup tape just doesn't last.

See:

http://www.clir.org/pubs/reports/pub54/

http://palimpsest.stanford.edu/byauth/lindner/tidal.html

http://palimpsest.stanford.edu/bytopic/electronic-records/electronic-storage-media/critiss.html

http://palimpsest.stanford.edu/byorg/abbey/an/an20/an20-6/an20-614.html

http://www.arkival.com/nml.html

Ron

[MARREEL Chris_1]

The lesson I learned from reading the documents Ron mentioned is : Tape is not realy a good medium for long term offline storage of data.

What other media is better to use ?
CD ?

Has anybody experience with CD-ROM media as long term storage ? Any opinions ?

Greetings,
Chris MARREEL

[Ron Kinner]

Turns out the name brands are much better for optical storage than generic by a fac tor of 10. See:

http://peripherals.about.com/library/weekly/aa041701a.htm

Ron

[A. Clay Stephenson]

Hi:

There is another aspect of this that must be considered and this applies to whatever medium that one chooses. That is the availability of hardware/software to read that media. It does very little good to have media with lives measured in tens of years when the technology or recording format is constantly changing and where 5 years is a very long time. I can tell you the best way to deal with this issue is to periodically import your data from offsite storage and transfer it to your current technology and then send both the original and the newer copy offsite.



Food for thought, Clay

[Peter Kloetgen]

Hi,

if you have to store your backup data for a very long time, you told us about 10-15 years, there are two mechanisms which you should combine: First you should take medias which can store data for a long time "relatively" sure. In these days CD-ROMs seem best here, they provide data "lifetime" of round about 7 years. ( Can be longer of course, but it's going to be not safe then... ) And you also could do a backup of your backups temporarily. So you could store your backup and the copies. Before doing backups of your copies try to find out if the media is allready poor, or if the quality is good so far...


Allways stay on the bright side of life!

Peter