plnelson wrote:
Could you elaborate on this? Why can't you use a bank safe deposit box? They don't have banks where you are? (a bank safe deposit box is what I use)
It's all about convenience. My nearest bank is several miles away, which is not conducive for regular backups (at least for me). If I went by it every day, no problem, but I'd have to make a special trip.
At the moment, there is no "Archive" technology capable of reliably storing terabytes of data for the long term.
Magnetic decay rules out both Hard Disk drives and Tape drives. After a decade or 5 of sitting on a shelf, most of the data will be corrupted. The best is tape and even that should be refreshed every year or two.
CD's and other optical storage tech is the only option. They don't have good capacities. But only need a refresher every 10 years or so.
Holographic storage is the best optical medium for long term archiving of lots of data. InPhase is currently the only producer of holographic storage drives and media. Currently up to 300GB per disk/cartage, and 50 years of reliably readable data.
It's not a happy answer but it's the truth. None of the options are great right now. Just pick the lesser of the evils.
I work for a company that, among other things, makes mass storage systems for extreme environments. The typical hard drive media will retain its magnetic state (data) for 10 years plus. With a strategy to migrate archival data to fresh media every few years, I would not worry about data retention issues rooted in magnetic 'decay'.
Drive densities are growing incredibly fast and the result is that the cost per byte is getting lower and lower. What I do is have a local backup on HD on a separate system, then copy that data to portable HDs for archiving. The archive drives are kept off site. My plan is to migrate the archive data to new drives every couple years. I have about 1TB of data at the moment. (although its growing pretty fast) If one were really paranoid, you could also make duplicates of the archive HDs. Its still cheaper than Blu-Ray and a lot more manageable.
I'll also note that companies that use tape for archives typically use a similar strategy. They migrate their data to new tapes periodically. There are software packages that keep track of where everything is and when it needs to be moved. It spits out pick lists for use by the offsite storage guys who pull the tapes and send them to the data center for migration. I don't remember how often this was done, but I'm thinking on the order of every couple of years.
The mechanical reliability of HD has been improving quite a bit. For example, the new bearing technology that was introduced a couple years ago did quite a bit to improve things. The automobile industry is now embedding HDs from Seagate into cars. Think about that for a bit. A car is a pretty nasty environment. Extremes of temperature, high levels of vibration, dust and dirt, etc.
