DVD vs Hard Drive

[Stelios Christofides]

Which one would last longer for archiving videos? Store them on DVD or on a Hard drive?

stelios

[Jim Andrada]

Let me turn the question around a bit

How long do you think you will store them?

If you're thinking a few months or a year or two, either will probably be OK.

If you're thinking 10 years, I think neither one is reliable.

Generally speaking, I'd go for a hard drive, but be sure to make two copies and also be sure to check the contents periodically. Monthly would be good, but probably nobody will do it. At least check the data once a year.

If you're looking for real long term archive, best thing around is LTO tape, but the drives are $500 - $1000. After that the tapes themselves are competitive with HDD.

[Frans Meijer]

Imo, harddrive.

No form of storage lasts really long and it is a lot easier to copy 1 TB of data from one drive to a new one then it is to copy 100 or 200 DVD's ...

[Stelios Christofides]

In other words you should replace your hard drives every 2-3 years to a new one and copy your data to this new one?

stelios

[Jim Andrada]

What I really recommend is a small raid array - some of them automatically scan the data continuously looking for errors which they can recover on the fly.

The problem with storing data on the shelf is that there is no ongoing error checking and recovery.

So one scheme that can work is to make two copies to HDD, then after 12 months or so copy the data to a third HDD and keep cycling around the three drives every year - this way by doing the copy, you have confirmed that all data is readable and recoverable.

Just letting drives sit around on a shelf for a few years is a good way to risk your data.

[Ronan O'Conghaile]

I'd go hard drive too. Easier to check it every so often and back it up a second or third time.

[Erik Norgaard]

Originally Posted by Jim Andrada

The problem with storing data on the shelf is that there is no ongoing error checking and recovery.

A good argument for harddrives, having your files "online" you have continuous access to monitor disk status, do background integrity check and recovery as well as fast migration to new media. Consider having to copy 1TB of DVDs to new DVDs compared to copying same size a HDD.

Some say that it's not good to have HDD lying on the shelf, that they should be used to stay operable. I think it's a myth that might once have been true in ancient times, but I doubt it with todays hard drives: The mechanics is in a hermetically closed environment, I don't see why it should not deteriorate faster by not being used.

After all these different media types, storage cost in free fall and data exploding, I don't think there is such a thing as a permanent archive, instead one should plan for continual migration.

BR, Erik

[Richard Lucas]

For 20 years I worked in computer storage and I vehemently disagree with those who say hard drive.The truth is that all hard drives fail, full stop. Given enough time, they will. It could be in a year or it could be in 10. The question is, do you want to bet on when? If so, what happens if you're wrong.

Optical is a better solution for archiving. Pardon me for being completely blunt but if you don't know the difference between fault-tolerance, back-up and archiving you don't know enough to intelligently ask this question.

What you are doing with your production content is running a mini-data center. One with a huge amount of data. The best way to find an answer you can comfortably live with is to learn a bit about computer data management. A little research will teach you that different media are appropriate in different stages in data workflow.

If you don't feel like doing the research, go optical, but tape is better.

[Brian Drysdale]

Any mechanical device tends to work better with use. Any of the experts I've heard recently have stated that bearings losing lubrication over time is the problem with hard drives.

Relying on a cheap hard drive to store your data longer term mightn't be the way to test a myth.

[Dean Sensui]

Even if you put all your eggs in a titanium basket, it's still one basket.

Even tapes can go bad, too. Everyone has seen a tape get eaten.

Always make multiple backups, whether it's tape, hard drive or optical.

And no matter what media you choose, be sure there's something that can read it in the future. Because even if the media is intact, it's no good if the system is so proprietary that no one has a working machine that can handle it.

[Brian Drysdale]

I transferred some old Works documents from my old computer, which could be opened there by Word 2003, onto my new computer and Word 2007 can't open them (even though it's supposed to).

The same thing happened with some old scripts done on Scriptware, that program couldn't open them on my new computer with the same program.

I had to use the old computer to create files of these documents that would work on the new machine.

[Jim Andrada]

Ahh yes, the infamous "future proofing" problem. This is a really big deal for archives. Ether you have to periodically migrate from older to newer technology or you have to get the PC related industries to stop making major changes/improvements every year or two. So since that's not going to happen, you're forced into a periodic migration mode.

One of the really good things about LTO is that in order to be certified to use the logo, all drives have to be able to read tapes written on two generation earlier machines and to read and write tapes made on one generation earlier machines. Also, we normally have three generations of drives in current manufacture so you should be pretty well assured that you will be able to buy a new drive that will read your old tapes for at least ten to 15 years after you write them. And service/spare parts will be available for at least 7 to 10 years after final manufacture. So if you write a tape today, you can good confident that you'll be able to read it back 15 to 20 years or more later. The new drives may use different attachment protocols etc than the old one (SCSI vs Fibre Channel vs e-SATA vs SAS vs who knows what) but the data will be readable). A hard drive on a shelf on the other hand offers no guarantee that there will be a system to plug it into even if the data is still good. Heck, we're already running into this with laptops no longer supporting Firewire for camera attach - even if you have a good tape in a working camera, no guarantee you'll be able to attach it to anything you can afford.

Which then sort of begs the question of whether the software that's out there in 20 or 25 years will be able to process the data that you just read back! Will Cineform still be around in 25 years? I hope so. I guess the key is to archive in really standard formats/codecs.

Also - I think we talk about archiving without really defining the length of time we want to be sure the data will be retrievable. The time horizon is really important - if our definition of an archive is something that I can recover a year or two or three later, it's easy. If we're thinking about digital assets with 50 or 100 year or more life spans, it gets to be a different kettle of fish altogether.

[Jon Fairhurst]

I think that a key part of the equation with digital is that you can - and possibly should - re-archive over time, including validation.

Hard drives aren't a bad strategy - if you include double storage and re-archive every four or five years. The nice thing is that sizes keep increasing. You might have 500GB drives one year and 4TB drives down the road. Each time you re-archive, it's possible that you consolidate into fewer and fewer - and less cost-per-byte - devices.

My archive horizon is forever... or at least my lifetime. The horizon of the specific media may be shorter. And that means that maintenance must be part of the plan.

If LTO were random access, I'd be more prone to consider it. Years ago, my wife and I backed up on to tape. It was expensive and time consuming. And thank goodness we never had to access any of it. Because it wasn't random access, we saw it as an emergency recovery system rather than a useful archive.

That was about 15 years ago. Hopefully, the tools have improved since then.

[Stelios Christofides]

This is really frightening. Everybody now is converting everything into digital form, books, pictures magazines e.t.c. Will my grand children be able to open these archived files? I am now busy taking pictures and videos of my grand children and store them in DVDs and hard drives. Will they be able to open and see these when they become adults? Thank god that I have the old pictures that my parents took when I was a baby. I can still see them with out using any electronic "gadgets" Thank God for the libraries. Books written by Greek, Egyptian and other historians and philosophers can be read today.

stelios

[Jim Andrada]

Well, yes, things have changed a bit

Current LTO drives permit drag and drop to copy files to tape. Not quit random access, but I think max high speed search time is on the order of 20 to 30 minutes (depending on the drive.) I'll check the details.

I know what you mean about old fashioned PC tape - when I moved back to the US from Japan I sold my blazingly fast 386 system to a friend and backed everything up to tape to restore on my US system. What a disaster! I stuck with it for easily 10 to 12 days and finally declared a victory when I had restored about 75% of my files.