I am looking into long term data storage for a friend, basically it needs to last 25 years. Money isn't an issue as its on an enterprise level. At the moment Im stuck for ideas. I know cds that are pressed are good to last for a long time. Other then that what are the options? Raid with yearly checks?
Sadly, yes. I've been lucky myself with CD's that have lasted me more than 10 years, but it's a good idea to copy that data to a fresh disc every few years. Or at the very least, make 2-3 copies. Unfortunately, if you really want to be sure about data, you need to check up on it.
Taiyo Yuden DVD+R can last up to 70 years if stored properly (cold, dark place) Add redundancy to that, and you're set. You can come back each 10 years and copy all the data to new discs, to be extra sure, it's cheap enough. You can keep backups on redundant hard disks and/or other magnetic media.
Wouldn't it be just as good to get a hard drive, throw your data on it, then seal it away in a safe or something?
What would be smartest/cost is just storing the data on vanilla hard drives (no RAID) with a complete drive parchive parity set (could take days to generate). For protection against mechanical failure you could make a redundant copy of each drive, any more would just be a waste of money. Hard drives can last mechanically over 20 years, but to be safe I would definitely move the data to newer drives every 10 years. If you are archiving lots of data, there is nothing more convenient than a hard drive, and nothing as immediately cheap except for magnetic tape, which has a much higher TCO in the long run.
Doesn't guarantee the data is safe. Data in a dormant hard drive is just as likely to be lost as if it were under heavy use. Multiple backups on different types of medias is a good way to go.
i think the problem with our "all numeric" society, is that most thing won't last long. Don't expect to show your grandchildren videos of your childhood. you dvd will be LONG dead ! that's the problem.
cheers for the ideas. Im guessing its not going to be an easy one, the safe options so far is to say the best option is a mix of media. The data has to last a Min of 25 years with out loss - This is governed by law with out it the project fails. File extensions too are getting me a headache eg which to use? which is future proof? A .doc made in the 1st version of Word is different to one made in the latest version. So fair only PDF files are said to be future proof with adobe suppoirting the file for 30 years.
Even a 25 year old document file in Wordstar is easy enough to convert and make into something useful. Probably a good idea to make copies of the programs too, just in case you do need something to open up some weird proprietry file format that some program has made. It's probably a good idea to back up (I would recommend a decent tape streamer that uses DAT technology) and refresh yearly as hoping something will be readable in 25 years time is asking for trouble.
Megneto-optical media, such as MO DISKS (but not flopptical media) is by far the safest type of medium to use. The main reason behind this is that for the data to change, there is a very high temperature needed, which never really occurs in domestic places! (unless a volcano errupts, fire catches or you put it in the oven) wiki it and you ll see the benefits for yourself.
The issue I have with them are and i quote "As with all removable storage media, the advent of cheap CD/DVD drives and flash memory has made them largely redundant." Are these going to be around in 30 years?
Firstly, there is no such thing as a 100% safe piece of data on ANY media. You have to ask yourself which media would last the longest, and to what conditions the media will be subjected. If it is possible it would be dropped, or kept near a magnetic source, a CD would fare better than a hard drive, for example. In answer to what you say about futureproofing, what WILL be used in 25 years' time still? I mean, IDE hard drives? Very unlikely. SATA? Also quite possible it won't be. SCSI? USB? Firewire? Who knows?!?! So the answer is, the media that is best for you is the one that will store the data with the most reliability AND WITH WHICH YOU CAN KEEP THE NECESSARY HARDWARE WORKING TO READ THE MEDIA IN 25 YEARS' TIME!! Are they going to be around in 30 years' time? No. Are CDs? No. Are DVDs? No. We'll be using holographic discs, no doubt. As they're not available, you'll have to pick a current, reliable technology, and hope you can keep the hardware running for that long, too!
Most companies do back up data to tape drives, mainly as they are cheap, reasonably fast (much faster then MO drives), reliable and are generally store the most for cost / size. Recent drives holding over 800gb uncompressed and if you have a large business you can get units which hold multiple tapes and can back up insane amounts of data. Tecnology has advanced but that quote is laughable though as hard drives have increased to the point that it would be painful to try and back up even a laptop hard drive on anything other then Blu-Ray, another hard drive or a decent tape drive. Evilways : Trying to back up even a laptop hard drive of say 120gb on punch card, say using the last industry standard of 80 column IBM punch cards (which would store about 120 Bytes per card ignoring any error correction or CRC checks) would require just under a billion of them. As each card takes up just over 2cm of cubic storage you would need an area the size of a village just to store them...
Although you would need about 12,000 reams of paper (a ream is 500 sheets) and even if you stacked them 3 metres high you would still require about half a kilometre of sqaure space.
