1. Excellent luck.

2. No idea. I am rotating mine every 3 years to be on the safe side.

3. No. 25GB on a single LAYER, 50GB on a dual Layer. No disk flipping.

4. No idea. I've used Sony, TDK, Verbatim, and Memorex. All have worked equally well. No coasters in 2.5 years.

My supplier of CD-R and DVDs http://www.prodisc.com.au/ quotes expected Lifetimes for most of his products, dependent on storage & handling conditions, and sells product specifically aimed at archiving. The guys there have researched the longivity of optical media very carefully.

My experience since the inception of CD-R is that "oils ain't oils" and many generic brand CDs I burnt in those early days have failed the test of time, until I started paying for premium disks..... since then, not one bad burn or subsequent problem.

I notice prodisc do not quote any lifetime for Blu-Ray or HD media yet. That speaks volumes to me.

Personally I trust Hard Drive more than Optical media. I backup to both, just to be sure, to be sure!

I've now got BluRay burned in 2007. It's fine. I checked it 2 months ago. All of it will roll to new disks Q1 2011. My first order of 3 50GB were $49.99 each. My first order of 25GB disks were 29.99 each. Today, I am paying about $1.30 for 25GB BluRay.

Christo,
I used to buy archival grade MAM disks from the same supplier. I've since found I can buy the same disks cheaper at PCX.
http://pcx.com.au/ProductDetail.aspx?ProductId=2050

Bob.

Thanks Bob!

One thing to consider about backing up to Blu-ray is that it is slow to burn and restoring a project to hard drive takes a long time, too. I only burn stuff to optical media if I'm pretty certain that I will never revisit the project. Otherwise, if I archive it to a hard drive, I can pop the hard drive in an eSATA dock and edit/modify the project immediately.

Also, for what it's worth, the program mentioned earlier is "GentibusCD" not "GenibusCD." It's available here:

http://www.gentibus.com/index.html

It's free and looks similar to the shareware program that I use, "WhereIsIt."

http://www.whereisit-soft.com

Thanks Bob

Pity they don't use PayPal

Well, 50GB takes an hour. That's about 3-4 times faster than laying off to tape for me. And a whole lot better quality. Certainly not as fast as hard drives, but fast enough for my purposes.

I archive things I don't think I'll have to touch again. I leave ISO files on the drives just in case I need to run more copies, but I wouldn't archive anything that might still need tweaking. Most of my corporate work is done for a specific event. After the event, the work is really no longer needed other than for historical purposes.

I bought enough disk capacity to sit on projects for about a year if I need to before archiving, but it's rare I'll need to leave projects open that long.

Thanks for the tip on Gentibus CD. Playing with it now, but looks pretty cool.

Yeah, I've been using BDs for video and backup since early 2008... basically, I bought my BD-R writer within a month of it being clear that Blu-Ray had won the format wars. The claim is that, due to the data redundancy, Blu-Ray is more reliable in the long term than CD or DVD, but obviously, the physical aspects have to enter in here, too.

I believe in redundancy for backup/archive. I have been dumping photos off to DVD, now BD, every so often. When I do the backup, I include all of my recent stuff, so every photo will be on at least 2-3 discs. And they normally live on a fully redundant RAID (I can hot swap one failed drive with no data loss).

Shelf Life? The easy answer: longer than Blu-Ray has existed. But this was also true of CD and DVD, and yet, you can find some discs don't last long at all. The big enemy of traditional optical discs is light... I keep my backups in a zip-up notebook with CD/DVD/BD acid-free disc holder pages, in a cool place with moderate humidity. I have one CD from 1991 that still reads (useless... it was for a Commodore CDTV, back when CD blanks cost $50). No reason to expect BD to be any worse. But don't bet on any single disc.

And BD has an advantage here, at least some do... the original BD-R discs use a non-organic optical dye, made of silicon and copper, rather than the synthetic organic dyes used in DVD and CD. The claim is they're not affected by light or other aging processes.

Size: 25GB for a BD25, single-layer BD-R, and 50GB for a BD50, dual layer BD-R. I haven't seen any dual-sided. That was a thing for DVD (DVD10, DVD18). A dual sided BD could hold 100GB, it they made one. Never seen it.. but anyway, the standard 50GB Blu-Ray Recordable is dual layer, not dual sided.

Not sure about best brand. For backup, this isn't a huge issue... you make new backups every week or few... right? For archival, I like redundancy.