several DVD questions

jack_nordine · November 25, 2012

I've always stored my Tiffs and raw files on DVDs. I buy Taiyo Yuden DVDs, and use the 4X speed when burning. I haven’t purchased blank DVDs in a while, so there are several questions I have. For long term storage, I believe DVD+R is a better choice than DVD-R. Would this be correct? And my second question is, if I’m burning at 4X, would it make any difference if I bought 8X DVDs or 16X DVDs? Thanks.

john_deerfield · November 25, 2012

Well, back when I used DVD's, the DVD-R was more archival. All the "Gold" archival DVD's I see are DVD-R's. Speed only matters if you are trying to burn at faster rates. That said, I quit using DVDs as a form of back up about three years ago. First, the media is simply too slow. It is too slow to record, too slow to verify, to slow to read, and too slow to copy back to a hard drive should I need to load the media off of the DVD. And to make things worse, a DVD isn't any safer than a hard drive. Meaning that if I go back to discs I burned, verified, and properly stored, I will have at least a 20% fail rate. At this point, I simply use a three hard drive system: primary storage and two back ups. Much faster and less expensive (I use bare bone drives) than DVDs.

danny_low · November 26, 2012

The archival gold dvd and blu-ray disks are all -R types so you really have no choice if you want archival quality. The speed only affects the time it takes to write the disk. The read speed is all the same standard speed.

I use blu-ray now for archival backup due to its higher capacity. The advantage of DVD/blu-ray is I can make copies and store them off site in a secure facility that can withstand the expected disasters such as tornados, hurricanes, earthquakes, etc. Having your archives in the same home or office as your computer does you no good if a Sandy rolls in and destroys everything. Archival does not mean photos you do not expect to use in the near future. It means a copy of the photo that you can retrieve if the original is lost. This means making multiple archival copies sometimes and it means storing the copies in a safe remote place. There are commercial places that provide rhis service. However a local bank safety deposit box is a good convenient substitute. Even if the bank building is destroyed, the vault is likely to survive.

Danny Low

andreas_weber · November 26, 2012

When was the last time you ran an integrity check over all those backup files you meticulously burned to optical media? Are you sure the images will all still be readable when you need them?

alan_olander1664878205 · November 26, 2012

Forget DVDs, etc. Use an external hard drive or two.

danny_low · November 26, 2012

Several years ago when external drives were getting really cheap and blu-ray was not yet available, I used an external drive as my archive backup. I stored the drive off site. One day I actually had to get a photo file off the drive. When I retrieved the drive and plugged it in, it would not spin up. I took out the drive and put it in another box and plugged that in. It would not spin up. Fortunately I had duplicate archival copies on DVD and found the file I needed.

Even hard drives fail. If you are serious about saving your files, do not make just one archival copy. Make several and store in them different safe places.

Danny Low

john_deerfield · November 26, 2012

Speaking for myself, I never said hard drive didn't fail. This is why I use three. The chances all three fail at the same time are remote. However, the point really is that ALL media fails over time: optical, flash, hard drives, tape systems, etc. The only protection from this predictable failure is redundancy. And once again why I recommend multiple hard drives: they are cheaper and incredibly faster than optical media. Copying images from a dual layer DVD takes a long time. I don't want to even imagine copying images from a blu-ray! And the cost and time it takes to make all of that? No thank you. I don't know how media and technology will change over the years. At some point, hard drives may not be the best answer. At which point I will need to migrate my data. Even now, the Mac mini and the iMac do not include optical drives. Now Apple is way ahead of the curve on this, but there will come a time you need to migrate all that data off of optical media. OMG, think of how much of an effort that is going to be. Now consider migrating all your data off a hard drive to whatever the future holds. And in terms of remote storage... store one hard drive in the bank vault!

jack_nordine · November 26, 2012

Thanks for all the responses. Several years ago I decided to try an external drive. I purchased a Toshiba model from Amazon. About a month later, something happened to the unit and I couldn’t retrieve anything. I called Toshiba and spent about 2 hours with a technician. He couldn’t resolve the issue. Bottom line, the unit was shot and I lost quite a few photos. Luckily, I had most of the important ones saved on dvd. After that experience, I’m hesitant to try another external drive. I guess it wouldn’t hurt to try another one or maybe two, possibly a better brand. That would give me redundancy. Right now, I just save to DVD and make 3 copies of everything. And one copy does go in my safe deposit box.

keith_b1 · November 27, 2012

"The archival gold dvd and blu-ray disks are all -R types so you really have no choice if you want archival quality."

No, you can get +Rs as well. The "gold" DVD+Rs I burned in mid-2007 are still fine.

"Copying images from a dual layer DVD takes a long time. I don't want to even imagine copying images from a blu-ray! "

Blurays are a lot faster than DVDs, assuming a fast-ish connection like FW800.

john_deerfield · November 27, 2012

Well, if we want to look at speeds...

8x DVD = 88 Mbits/s.. cost per GB = .15¢ give or take

6x blu-ray = 216 Mbits/s (yep, that's faster)... cost per GB = .14¢ give or take

A "typical" 7200 rpm hard drive = 1030 Mbits/s (uh... if we are talking speed)... cost per GB = .07¢ give or take

In terms of cost, this also means you are taking full advantage of the capacity of the optical media. In my experience, this is unlikely. We tend to "burn" as we need to not as capacity dictates. Which simply drives up the cost of optical media even more.

Again, since any media IS going to fail, I fail to see why I would want to take the time and trouble creating redundant copies of optical media that consumes more of your time & money? Additionally, optical media requires even more time when you consider you have to "build" the disk you want to burn. As compared to simply using some sort of back up software. I simply insert one of my back up drives and the new data is automatically copied. Done. Painless. For an optical disc, I need to "track" what still needs backed up and build the disc to burn it. It doesn't matter how you slice and dice it: optical media is slower and more expensive than simply using a hard drive system. It isn't a matter of which one is safer because you will need redundancy regardless of methods. As such, why not use the cheaper & faster redundancy method?

EricM · November 27, 2012

Backed up and archiving are approached by me differently. I think it's foolish

to put faith in just mechanical drives. Yes, they're fast and cheap and easy,

but they are the most vulnerable on every front. A back up strategy should

have a min of two different types of media anyways.

danny_low · November 27, 2012

There is agreement here that all media can fail but what happens when a 1TB hard drive fails versus a 50GB blu-ray disk? With the HD you lose access to 20 times the data. That is also a good reason not to fill any disk to capacity when archiving. You fill a disk with a logical grouping of files and you will lose only those files. Say you put one day's worth of photos per DVD and one DVD fails. You lose only that day's photos. You fill a disk with all the days for a trip and you lose the entire trip.

The time to archive is purely secondary. You archive files you do not expect to use again. You backup files that you expect to use again. That is a very important distinction which some postings here obscure. If you are in the business, then the distinction matters. If a tornado or hurricane wipes out your office, all your current files and backups will be gone but your archives will be intact if you stored them in a safe off site location. If you are not in the business, the distinction can still be very important if what is in the archives is your family's history dating back a 100 years. I have helped people digitize old prints so those family records will not be lost. Some are more than 100 years and are of historical value to people outside the family as well.

For backups of current working files, hard drives are the way to go. To archive files to save them for prosperity you should use a media that lasts and can be stored off site. DVD and blu-ray fits that requirement better. So the OP should first ask if he is really archiving his files or just backing them up? Backups are only for if your working system stops working. Archives are for when your entire office goes away as when a tornado takes it away.

There are times, such as when backing up daily vacation photos, when backups and archives are efectively the same. But for the office, they are different and they require different methods. The recommendation I make here are for archives not backup. As I wrote above I use hard drives for backups and fill them to capacity. For archives I use blu-ray and fill them logically. Most important of all, I store archives in protected locations.

Danny Low

john_deerfield · November 27, 2012

but what happens when a 1TB hard drive fails versus a 50GB blu-ray disk?

</blockquote>

You lose your data. Assuming a full 1TB worth of data, it will take maybe 90-minutes to copy off one of the back up drives. Assuming 50GB on a blu-ray... now you need to figure out what 50GB you lost. Then re-burn it. I imagine that will take at least as long. Assuming 50GB discs, you now have 20 discs, simply increasing your chances that one of them will fail. Archive or Back Up, hard drives are faster and more cost effective. I think what we aren't talking about is data migration. Methods will change and evolve over time. At one time we had 5 1/4 floppies. I moved a LOT of floppies to 3.5" discs. I probably have a several thousand "back-up" or "archived" CD's. I don't have the time to migrate that data to hard drives. Right now, hard drives are the best, most effective means of data storage. When that isn't the case, it will be time to migrate the data to what is the best. But imagine that is in 10 years and imagine I have a hard drive for each year (and two back ups) or I have hundreds of blu-ray discs.... which do you seriously want to migrate? If one drive fails, I go to the other, if that fails I go to the third. If that fails, yes, I am SOL. If a blu-ray disc I burned in 2012 dies on 2022... I probably won't even know what was on it. Let alone migrating all of those discs.

danny_low · November 27, 2012

John

This is the 3rd time you have posted essentially the same information restating the same point. We get it. Clearly there is no point in any further discussion on recording speed. As I pointed out, speed is not essential for archives. It is only essential for backups and the two are not the same. I am talking about archiving data, not backing it up.

The one new point is what will be available in the future and that is really unknown. Back when floppies were the backup and archival medium, optical disks did not exist. Hard drives were so expensive and so small that using them was laughable especially as there was a hard 4 drive limit on a PC. The medium of choice if you could afford the high cost was tape. I was doing backups and archives for companies back when it was all reel to reel tapes. Nothing that we use today existed back then.

Whatever will be the backup or archive medium of the future will probably be something that does not even exist today. Blu-ray has one advantage over hard drives though. It is a defined consumer standard that is in wide use today. That means it will be supported far into the future. Any blu-ray player will play DVDs and CD. However no PC today supports ST506 hard drives even though they were the standard back when floppies were around. This means if you had archived data on a ST506 drive you cannot find a modern PC to hook it up to. OTOH any optical drive today can still read the CDs you created back then. So for really long term archives, blu-ray is a better choice as you will be more likely to find something to read it in the far future than any hard drive.

And again, speed is secondary for archives. Retrieving data from the archives is not even an annual event for most people. It is more like once every 10 years.

Danny

otto1 · November 27, 2012

Danny,

John is valid in emphasising this point.

We do photographic scanning on a large scale and nearly all of the bigger jobs get delivered on hard drive, smaller ones on DVD. However, we emphasise to every client that it is not permanent media.

Every electromechanical storage system will fail, without exception. Hard drives are specified with a MTBF (Mean Time Between Failure) which covers a range that includes the first hour or many years, but it will fail.

My main point to make to you is not to trust the long term market presence of BluRay. We have never had one request for it in the past decade. It is in some computers by special order only. It is used for delivery of movies, but that is being fast supplanted by broadband. (I did some research and talked to several chaps in an associated IT support company with hundreds of clients if they know of anyone who uses BluRay for storage, and there were shaking heads all round.)

BluRay was crippled in the war with DVD-HD, and most markets ignored it.

Hard drives are far cheaper, and much easier to use. In most parts of the world, 1 TB is less than $100.

I have seen standards come and go in my own 35 years in IT, similar to yourself. It is not a question of what will be good in 35 years time, but how will you migrate progressively.

Of course, the only true archival media for photography is film, but Kodachrome is gone. My business scans glass plate negatives and positives that are a hundred years old, and are still great.

If you want permanence, etch platinum plates with the digital information of a TIFF file, along with how to rebuild it to a digital image.

otto1 · November 27, 2012