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Quite frankly data is so duplicated today bit-rot is not really an issue if you know what tools to use, especially if you use tools like quickpar on important data that can handle bad blocks.

Much data is easily duplicated, the data you want to save if it is important should be backed up with care.

Even though much of the data I download is easily downloaded again, the stuff I want to keep I quickpar the archives and burn to disc, and really important data that is irreplacable I make multiple copies.

http://www.quickpar.co.uk/

check this link for some problems with ICE ECC

http://www.quickpar.co.uk/forum/viewtopic.php4?t=6 19&highlight=ice+ecc

I think Quickpar is still better, especially if you use it on iso's rather than individual files.

Hard drives are excellent for daily backups, especially if you swap drives weekly (where you have either 3 or 4 generations).

Still no substitute for periodically archiving data off to DVD-R and adding additional recovery data using QuickPar. That's a good way to ensure that you can recover from disc scratches that are too much for the built-in error correction to handle. (Also a good way to verify that your data is still correct since it stores hashes of the protected files.) The purpose of archiving is to provide long-term (as in months/years) snapshots of your data.

If you burn your own DVDs, you can even protect the contents of the VIDEO_TS folder. Which is not a bad way to use up the remaining disk space on a not-quite-full DVD.

DVD is fine for long-term archival, especially if you add parity data to the disc. (I usually add 5-10% recovery data to allow for discs getting scratched or otherwise damaged.) I find CD/DVD (and back when floppies were realistic) to be too much of a hassle, which means that backups don't always get done.

For day-to-day backups I use 250-300GB 5400rpm drives in removable caddies (StarTech.com's DRW115 series). Base unit is $60 or you can buy the components separately: extra bays are $20-$30, extra caddies are $50-60. By rotating 3 or 4 of those drives, I have the convenience of tape without the cost of tape.

Combine that with software like Second Copy 2000 (sits in the system tray, plays nicely with the system, does backups in the background, doesn't use a proprietary storage format) and you have something that simply works. No muss, no fuss, and no procrastination.

I recently tried to load a few old CD-Rs that had been lying around for a while... nothing. Errors all over the place. Will this thing be useful for archiving stuff or only for same-year viewing?

The solution for this (if you don't want to burn everything twice) is to put additional recovery data on the disk. Current, the best program is QuickPar.

The idea is that you collect 600MB of data for archival onto a CD-R, then you generate another 95MB of recovery data that will protect the original 600MB. As long as the disc never suffers more then 95MB worth of damage to the data blocks, you can recover from any scratches or other damage. Adjust the amount of recovery data up/down depending on your paranoia level (I prefer 5-15%).

Caveats: Only works for data CDs. Works well for video DVDs (e.g. to protect the content of the VIDEO_TS folder). Does not understand sub-folders (yet), so it works best if all files are in a single folder (e.g. the root folder). Creating a recovery set for a DVD-R takes 30-90 minutes on modern PCs. Creating a PAR2 recovery set for one of these 50GB monsters will take a few hours.

Anyway, now I'm burning *a lot* of DVD-Rs to fair use archive my favorite TV shows (about 1-2 discs per day, sometimes more). I'm being very careful to keep them in a case all the time, away from dust, not touching them, and I probably won't play them all that much.

It's possible to add recovery data to video DVDs using QuickPar.

Leave about 200-400MB free in the VIDEO_TS folder on your hard-drive when you author (so shoot for 4GB worth of VOBs). Use QuickPar to add PAR2 recovery data to protect all of the files in the VIDEO_TS folder, using a block size of 1024MB or 2048MB. Then burn the VIDEO_TS folder contents plus the PAR2 to the DVD.

Some folks move the PAR2 data out of the VIDEO_TS folder, but the few DVD players that I've used don't complain if I leave the PAR2 data in the VIDEO_TS folder. (Which makes it easier to verify the contents of the disc if the PAR2 files are in the VIDEO_TS folder.)

Yeah, it's a bit of work and you can't use the built-in burning software with most DVD authoring packages. But the end-result is worth it when your DVD disc gets scratched down the road.

My first CD-Rs (over 10 years old) also still work perfectly. Some simple rules I follow are:
- Buy CD-Rs withouth printed label (the printing process causes material stress)
- Burn them at low speed (the lowest my current burner allows with my SW is 8x)
- Verify the data after writing (very important!)
- Always be careful with the label side (e.g. don't put that side on the table, dirt could cause scratches)
- Prevent hot temperatures and direct sunlight

Good, but you should also add recovery data to those CDs using QuickPar.

Right now, once you discover that your discs have been damaged, it's too late to recover the data files that have been stored on the discs. With the addition of recovery data, you can add a "window of recovery" which allows you to correct errors that are too much for the C1/C2 error correction to fix. Depending on your risk-averseness, you can make that recovery window larger/smaller by including more/less recovery data.

Some folks even spread the PAR2 files across multiple disks, say taking 5 disks of data, creating 40% recovery data (2 additional disks worth), and then evenly spreading the 40% recovery data and the protected data across 7 disks. In that scenario, you can physically lose up to 2 disks and still get your data back.

When I have something to send somewhere, and I have to be sure it works, I just make 3 copies of it in directories 'copy1' 'copy2' and 'copy3' on the CD. A while ago I would lose copies of Windows98 on CDs because of the messy environment and (temp + humidity), so I'd burn multiple copies on the same disk. Almost 9 years on, I found a disk containing Quake2, the first and third directory were bad, and the second directory had just one file that was bad. I found a good copy of that file in the third directory. The CD didnt look like one byte could be read from it.

Bit wasteful of space... (I've done it too with floppies in the past). Another alternative would've been to add 20% recovery data to the disc using QuickPar. Then you could've simply repaired the damaged files. You can even do things like rip the entire disc to an ISO file (including the damaged sectors) and QuickPar will extract all of the file information and do the repair. (The fixed files get written out the to current directory.)

Blank CDs in bulk are cheap. For archival stuff I make a new copy every 5 years. I have a bunch of scanned photos I don't want to lose, so I re-copied them all onto new CDs.

You should be adding recovery data (e.g. using QuickPar) to those archival CDs.

The big advantage is that it extends the time window during which you can recover all of your data. Without PAR2 files, once you find fatal corruption of a file, you're done and the data is gone. With recovery data, you can repair the damage as long as you have enough recovery blocks.

(PAR2 also makes for a good, quick, verification tool that you can run against the content of your disc to verify everything is still correct.)

Convert them, and keep the 8mm tapes in a cool, dark, dry place.

One trick for DVDs is to stick PAR2 recovery data on them using QuickPar. Then, once the ECC on the disc can't keep up with the scratches, you have a window of opportunity during which you can repair the damage using the recovery data. The more recovery data there is on the disc, the more damage that can be sustained and still repaired. Only a scratched ToC track is difficult to recover from (have to use a professional service).

Basic steps:
1. Create the VIDEO_TS folder using your DVD authoring program. Leaving 50-250Mb of space on the DVD instead of aiming for the abolute max is probably a reasonable amount.
2. Create recovery data (PAR2) files in the VIDEO_TS folder, using a block size of 1/2/4Mb with enough recovery blocks to fill out the rest of the DVD's capacity.
3. Create an ISO file using ImgTools Classic.
4. Burn the ISO file to DVD.

I haven't had any issues leaving the PAR2 files in the VIDEO_TS folder, but YMMV. (Leaving them there makes it easy to verify the discs a year or two down the road when you suspect damage.)