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| Thread ID: 21298 | 2002-06-22 07:30:00 | WhatÂ’s the lifetime of digital storage methods? | rugila (214) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 56406 | 2002-06-22 07:30:00 | In principle it’s forever, since the numbers one and zero will presumably be the same in a million years time as they are now. But what about available practical techniques of storing digital material for long periods? Storage in ram doesn’t last long at all, on floppies and hard disks maybe for a few years (I still have an old 1991 85mb Maxtor, still works 100percent but effectively useless because of low storage capacity). Tape has a limited lifetime - I don’t know how long, likewise if write CD how long does this last for? Any (helpful, ie not pen and paper) suggestions anyone? I still have old family photos from about 1912 (I didn’t take them) that look OK, so that kind of (analogue) storage can obviously last a long time under good conditions. What is the lifetime of a CD or DVD kept under good storage conditions? Are these the best means of archiving digital data over extremely long periods of time? Obviously transferring the data periodically to more updated storage media is a good idea, but how frequently? What’s the best way to approach this whole topic? |
rugila (214) | ||
| 56407 | 2002-06-22 07:39:00 | My understanding is, tape based medium (includes floppies) 10 years CD/optical depends on type of substrate but 100 years for good quality. I remember when CDs first appeared, they were worried that 10 years was maximum due to corrosion on the aluminium substrate, but that hasn't happened. Remember that stamped CDs are very different to burnt CDs, which are die based and may not last as long. In 100 years will you still be able to readily access the medium (any medium)? Suppose you had a large collection of recordings on magnetic wire (forerunner of audio tape), how would you play them now?? If using CD, the problem would be most likely could you find anything to access it on, not will it last. Write it down, we can still read info from centuries ago |
godfather (25) | ||
| 56408 | 2002-06-23 04:55:00 | NASA have many millions of 2400' 0 . 5" tapes, recorded in 7track 556bpi, 800 bpi, 9 track 800bpi, 1600bpi, and 6250 GCR . They are transferring them to CDs . The life for magtapes is pretty good -- normally the reels should be rewound every two years, and kept in controlled conditions . Floppies should be OK for 5 years if they're looked after . 1/4" tapes about 5 minutes ;-) . CDs : they are claiming 100 years or so . It has not been tested, except by extarpolation . The recordable ones (and RW -- which *might* be less robust) should be kept in the dark, or at least away from UV and extreme heat . |
Graham L (2) | ||
| 56409 | 2002-06-23 07:21:00 | If I save anything to floppy disk now I alway save several copies, one of them is usuall bound to have a error on it. I would also adopt the same policy with CD's, if the data is important then make more than one copy. | Tristan Speak (465) | ||
| 56410 | 2002-06-23 09:18:00 | Have a look at the following site,It may shed some light on the matter, cheers Steve www.cdmediaworld.com |
Steve Askew (119) | ||
| 56411 | 2002-06-24 04:13:00 | I had a 8 tarck tape that became unreadable after about 15 years even using reduncy recovery. CDs of all type need to be kept dry (low humidity) - There have been trials where they became useless after 6 months at high humidity as moulds grew on them. One suspects - but there is little evidence that stamped CDs would be longer lived than dye based. It seems that the basic HDD drive may actually be able to store stuff longer albeit at greater cost. The old story Cheaper, Faster, Better pick any two. I still have a deck of puched cards and some paper tape that would read ine if I could find a PC with the right reader ;-) |
jst_nz (559) | ||
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