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Life Expectancy of digital storage media

PostPosted: Wed Jun 21, 2006 10:11 am
by BT*ist
CDs/DVDs may have a lifespan of as little as two years (up to five) according to this article. Is anybody worried about this? Does anybody have a storage and backup strategy that involves more reliable media?

http://www.smh.com.au/news/cameras--videos/burning-for-the-long-haul/2006/06/14/1149964545127.html

I keep my DVDs in a cool(ish), dark place, but I have had one DVD develop some kind of milky, spotty sheen on the reverse (!) that rendered all but a few photos unobtainable...

PostPosted: Wed Jun 21, 2006 10:18 am
by Michael
I wonder if the life expectancy would be increased if you put it in a vacuum in a dry place.

PostPosted: Wed Jun 21, 2006 10:53 am
by redline
whats about cf cards?

PostPosted: Wed Jun 21, 2006 12:11 pm
by Steffen
Archival stability of recordable media is an issue, and yes, I am worried.

Some random links I've saved about this:

US Govt study on optical media stability:
http://www.itl.nist.gov/div895/gipwg/StabilityStudy.pdf

Manifest-Tech article on DVD longevity:
http://www.manifest-tech.com/media_dvd/dvd_compatibility.htm

Verbatim announces archival grade DVD-R media:
http://www.dmnnewswire.com/articles/viewarticle.jsp?id=38076

Alternatively, you can backup to DLT tape, but the drives are very expensive.

Cheers
Steffen.

PostPosted: Wed Jun 21, 2006 12:34 pm
by Grev
There is no way to safely backup everything but to make multiple copies though.

Not sure about the time flash memory or hard disks lasts... But optical disks can deteriorate really easy if misplaced.

PostPosted: Wed Jun 21, 2006 12:35 pm
by Nnnnsic
Well, DVD's suffer from the archival issues worse than most mediums... go organic azo rot!

Really, there's piss all we can do about it.

Store it on a spare hard disk and pray it doesn't break when you need to use it.

Re: Life Expectancy of digital storage media

PostPosted: Wed Jun 21, 2006 12:42 pm
by greencardigan
BT*ist wrote:CDs/DVDs may have a lifespan of as little as two years (up to five) according to this article. Is anybody worried about this? Does anybody have a storage and backup strategy that involves more reliable media?

Put a yearly reminder in your calendar to backup your backup. That way your DVD backups will never be more than a year old. 8)
DVD's are cheap.

As far as I can see this is the only cheap way to overcome the DVD lifespan problem.

PostPosted: Wed Jun 21, 2006 12:45 pm
by Alpha_7
Nnnnsic wrote:Well, DVD's suffer from the archival issues worse than most mediums... go organic azo rot!

Really, there's piss all we can do about it.

Store it on a spare hard disk and pray it doesn't break when you need to use it.


Use magnetic tape, is has a better life-cycle and also takes up less space per 100gb then dvds would.

PostPosted: Wed Jun 21, 2006 1:54 pm
by Steffen
Alpha_7 wrote:Use magnetic tape, is has a better life-cycle and also takes up less space per 100gb then dvds would.


You have to be careful, though. Pure metal tapes (like DDS, and I suppose Travan etc) are not archival. Once their protective coat is scratched or cracked they'll simply rust away. The DDS tapes I use at work always die within two years.

Metal-oxide tapes (like DLT, SLT, basically the $50+ per cartridge stuff) is usually archival, but check the vendor specs!

Cheers
Steffen.

PostPosted: Wed Jun 21, 2006 1:59 pm
by birddog114
Steffen wrote:
Alpha_7 wrote:Use magnetic tape, is has a better life-cycle and also takes up less space per 100gb then dvds would.


You have to be careful, though. Pure metal tapes (like DDS, and I suppose Travan etc) are not archival. Once their protective coat is scratched or cracked they'll simply rust away. The DDS tapes I use at work always die within two years.

Metal-oxide tapes (like DLT, SLT, basically the $50+ per cartridge stuff) is usually archival, but check the vendor specs!

Cheers
Steffen.


Steffen,
I'm with you on this: only tape or media with metal-oxide, other than that they're garbage, won't last long.

PostPosted: Wed Jun 21, 2006 2:03 pm
by Alpha_7
The ones we use are Super DLT (either Quantum or Dell, they come from the same factory just different badges). I'd still have more then one copy in the archive, as tapes can have issues too, but other then that it's would seem to me to be a safer option then relying on CD/DVDs. I'd suggest not storing them near stong magnetic fields though :shock:

PostPosted: Wed Jun 21, 2006 2:04 pm
by losfp
Hard drives would seem to be the most cost-effective way. Back 'em up, then unplug and store in a dry cabinet or something :)

Plus of course have 1 or 2 DVD copies stored in a separate location.

I really should back up my stuff properly. At the moment, it is all simply kept on a 2-drive mirrored RAID array on my fileserver. However, if struck by lightning, fire or thief, it's all gone.

PostPosted: Wed Jun 21, 2006 2:10 pm
by birddog114
Alpha_7 wrote:The ones we use are Super DLT (either Quantum or Dell, they come from the same factory just different badges). I'd still have more then one copy in the archive, as tapes can have issues too, but other then that it's would seem to me to be a safer option then relying on CD/DVDs. I'd suggest not storing them near stong magnetic fields though :shock:


But how many people among us can afford this way? using Super DLT or DLT, SLT, not only the drive is expensive but also medias are a no go.

We talked about this before on this forum related to backing up, archiving etc...

Depend on how deep your pockets are, RAID, Hdd, DVD are common thing for us to use. If you're lucky then the tape system as abovementioned are my recommendations.

PostPosted: Wed Jun 21, 2006 2:13 pm
by admajic
Ive had terrible experiences with DVD-R I thought that they would last. Backed up some movies and 3 months later the disk isnt even recognised. Others from the same batch still going strong.
Ive found CD-R disk I have from over 10 years ago and they still play fine. Maybe its luck?

PostPosted: Wed Jun 21, 2006 2:15 pm
by birddog114
Alternative is: commisioning 02 x RAID 5 (NAS or SAN) and synchronize them daily.

PostPosted: Wed Jun 21, 2006 4:46 pm
by terminator
Download all your images onto Flickr and let them worry about it!! :)

PostPosted: Wed Jun 21, 2006 5:38 pm
by apsilon
losfp wrote:Hard drives would seem to be the most cost-effective way. Back 'em up, then unplug and store in a dry cabinet or something :)


I used to do this. I recently (2 months ago?) pulled a HDD out of storage (sealed in antistatic bag and kept in a padded box out of the way) only to find it dead. Being a little concerned I then pulled 2 others out of storage to find them also dead. They'd been in storage for between 5 and 2 years. One dead drive, OK. 3 dead drives is weird. Luckily none of the data on them was important and I had other backups.

I think the only way to be sure is to backup to multiple media and renew those backups regularly. keeping one offsite at a friends or family member would also be a good idea in case of fire etc.

PostPosted: Wed Jun 21, 2006 6:14 pm
by BT*ist
... and printing to photographic paper is also a form of backup... poor substitute though they might be, photos can be scanned again to recreate a version of the original digital file...

PostPosted: Wed Jun 21, 2006 7:22 pm
by whiz
The listed studies of the optical media will tell you why your DVD's aren't lasting. DVD's all use the least reliable dye layers. Some of the older lower speed CD's will be around for quite a while.

PostPosted: Wed Jun 21, 2006 8:05 pm
by moz
I just do the simple thing - roll forward my backups every time a new format becomes established. Since I build new machines roughly every 18 months I take the opportunity to verify the backup at that point. Often I sit down and purge the backup of duplicates, then merge it to remove updated files (or merge them, ifn there's stuff I didn't want to lose after all). Then I back up the new "packed" archive. Last time I did this was the shift to DVD about 2 years ago, but since then I've done a complete restore about a year ago (less than 1% disks with any failure).

I suspect I'll be dumping my 250GB SATA drives soon, replacing with 750GB, and at that point I'll redo my backup.

In order from most faith to least, I trust: tape, CD, DVD, spinning hdd, stored hdd. Unfortunately, the cost of tape is horrid, and CDs are even more expensive (even at only $5/hr for my time). So I use DVDs and RAID.

PostPosted: Wed Jun 21, 2006 8:36 pm
by Colcam
A very valid concern these days with the sheer size and quantity of digital data being generated by the various graphics areas of computing. I have a 2 x 200gb SATA drives in mirrored Raid array, plus a 150gb HDD just for photo's as well and the data portions of these drives are auto backed up to a 250gb external HDD as well as being regularly burned to catalogued and indexed CD & DVD (with regular replacements) and a hard copy of each print on archival paper filed away.
The lack of permanence in optical media is a big worry. I am about to go to another larger external HDD in parallel to the 250gb to alternate the backup day in case I corrupt or lose a drive.

Stay alert and be careful!!
Col

PostPosted: Wed Jun 21, 2006 10:57 pm
by Steffen
apsilon wrote:
losfp wrote:Hard drives would seem to be the most cost-effective way. Back 'em up, then unplug and store in a dry cabinet or something :)


I used to do this. I recently (2 months ago?) pulled a HDD out of storage (sealed in antistatic bag and kept in a padded box out of the way) only to find it dead. Being a little concerned I then pulled 2 others out of storage to find them also dead. They'd been in storage for between 5 and 2 years. One dead drive, OK. 3 dead drives is weird. Luckily none of the data on them was important and I had other backups.


That's weird. What could kill the disks in 5 years? Firmware flash gone bad? Do they even store their firmware in flash memory? Maybe the bearings got stuck? Or the heads on the platters? Did they spin up at all? A hearty wrist flick or two can usually unstick them...

I was just starting to think that with 200GB HDDs for $100 or less, this isn't only an economical but also the most space conserving means of storage...

Cheers
Steffen.

PostPosted: Thu Jun 22, 2006 8:04 am
by birddog114
apsilon wrote:
I used to do this. I recently (2 months ago?) pulled a HDD out of storage (sealed in antistatic bag and kept in a padded box out of the way) only to find it dead. Being a little concerned I then pulled 2 others out of storage to find them also dead. They'd been in storage for between 5 and 2 years. One dead drive, OK. 3 dead drives is weird. Luckily none of the data on them was important and I had other backups.


Perhaps, you overlooked the "Expiration date" or "Use by date" imprinted on the its label thru X-ray :lol:

PostPosted: Thu Jun 22, 2006 9:03 am
by Matt. K
A timely thread as I have just experenced a major hard drive failure and know from experience the sinking feel you get in your guts. I have lost some work but not a large amount. It's plain to me that hard drives are not a reliable form of storage in themselves and that a multiple storage system is a must. The most appropriate approach is to identify those images that are priceless from those that are simply 'worth keeping' and never put yourself into a situation where you have less than 3 copies of your priceless pics.

PostPosted: Thu Jun 22, 2006 9:46 am
by apsilon
Steffen wrote:That's weird. What could kill the disks in 5 years? Firmware flash gone bad? Do they even store their firmware in flash memory? Maybe the bearings got stuck? Or the heads on the platters? Did they spin up at all? A hearty wrist flick or two can usually unstick them...

I was just starting to think that with 200GB HDDs for $100 or less, this isn't only an economical but also the most space conserving means of storage...

Cheers
Steffen.


Spin up fine then click, click, click.....

No idea why they'd die just laying dormant, they weren't subjected to any shock or extremes of temperature. They weren't brand new drives when they were put into storage so who knows. The only thing I can think of is that something rusted and either got stuck and/or broke when powered on. I have no way of proving it but I think if they'd been kept spun up they'd have been OK but that's not very practical.

I think tape backup plus another form is the way to go but unfortunately tape solutions aren't cheap. Cheaper option is a NAS box with RAID kept on site and regularly updated DVDs off site.

PostPosted: Thu Jun 22, 2006 11:53 am
by Ivanerrol
Just for interest I re-installed some old disk drives that I had replaced with updated models. e.g Old 4 GB and 10Gb drives that I replaced with 30 and 80 GB drives. They were working O.K. when I removed them a few years ago. Now - Nothing - unreadable.
I have also checked some CDs I burned a few years ago with scanned negative images. I used cheapo CD's bought at a computer swap meet. Also unreadable. Lucky all images on raid array in my server.

All previous posts regarding backup to disk etc etc all seem to be made by computer literate members. How about all those people out there who have bought P&S digicams and committed their images to CD or to disk drives and are not sufficiently computer literate to do backups and reburn CD's before use by date?

Do any members here who shoot weddings with still or video and then supply their customers with photo CD's and Wedding DVD include a disclaimer that the media that they supply is not gauranteed to keep the images? I know if I had paid up to $ 5,000.00 or more for a wedding video DVD that was unreadable in 5 years or more I would not be too happy.

PostPosted: Thu Jun 22, 2006 12:38 pm
by DaveB
It's worth mentioning that disks that have had a long and active life (e.g. maybe the 4/10GB disks Ivanerrol's referring to) are probably more likely to fail during storage than ones that have had much less use. For a start the lubricants will be in different condition.

I back up my files to external disks which are stored off-line, but those aren't my only copy. I have two (I should update it to three :roll:) sets of disks. One stays online all the time connected by Firewire, and I regularly plug the backups in (typically via USB2) and resynchronise.
So far I've got a small enough set of disks (and each one is big enough that it's likely that SOMETHING on it has changed) that I'm not tempted to leave the backups on the shelf for long periods. I haven't noticed failing offline disks yet, although I'm sure it'll happen at some time.

I have several exposures to loss at the moment:
  • Failure of a primary disk (or accidental deletion/etc) before the files have been copied to the secondary.
  • Failure of a secondary that's only discovered when trying to recover files from it.
  • Catastrophic failure while the secondaries and primaries are being resynchronised. This is mitigated slightly by only connecting and synchronising one secondary disk at a time).
Having a 3rd copy of the files will reduce these risks significantly, but even as it is I have a reasonable level of protection. Having hundreds of DVD-Rs is not an attractive proposition for me (especially as these will require regeneration over time). CD-Rs are generally better for longevity, but still require regeneration and will number in the thousands. I retired my CD archives a few years ago when it got unwieldly. A 2nd set of secondary disks is the path I will probably go down, although right now I've just had to add another primary+secondary so need to build up the funds again and weigh up the risks.

Having only one copy (on a hard disk) of my files would scare me, no matter where the disk is stored.