Is optical media storage more stable than magnetic media storage?

[bevills1]

Recently I tried to import address books for both Outlook Express and Mozilla mail from 2 different folders I'd saved them on hard drive, but error messages were given in both Outlook Express and Mozilla mail. Then I tried importing from CDRW I'd saved them to, and both address books were successfully imported without problem. This must mean files saved in hard drive folders had become corrupt. Also periodically Windows checks certain disks during boot and corrects errors if errors are found which may cause file corruption. Has anybody else had similar experience with file corruption on magnetic media but not on optical media?

[lordsmurf]

Media quality is far more important than media format.
All things considered, however, optical is far superior for many reasons.

[oldandinthe way]

Magnetic media is more reliable than CD-RW.

That said, the liklihood of a backup on any media going bad is less likely than the chances of a file on an active disk going bad.

A single session CD-RW is more reliable than multisession. A hard disk used solely as backup is more reliable than your system disk.

Screw up the directories or allocation tables on your hard disk and you will be unable to access files which are complete and intact. If windows runs chkdsk or scandisk, and fixes the directory structure data may become inaccesible.

The liklihood is that your data loss on the hard disk is due to the file system, not the media.

[Video Head]

Stable is an awkward word when describing data integrity.

Bear in mind that a hard drive is both a mechanical device and data storage medium all in one. The data is stored on magnetic platters that spin at high speed. The drive has an arm that swings across the platters, much like a record players arm did, reading and writing data from various spots on the platters. The difference is the speed involved. To give you an idea of the speed involved: a typical record would spin at 33rpm. A typical modern hard drive spins at 7,200rpm. My 325HP V8 redlines at 6,800rpm...7,200rpm is fast! And some spin at 10,000rpm +. The arm also moves at an incredible speed, not tracking like it would on a record, but jumping around to extract or write data in various spots on the platters. So you have platters spinning at high speed while an arm is moving at high speed to various locations on the platters to extract and write data. All it takes is one bump and the arm goes off a little or bounces off the platter surface and your data is corrupted...then there is the fact that the drive can just plain out suffer a mechanical or electrical failure or one of the platter surfaces may have a flaw...so many things to go wrong. That is why servers that store critical data use RAID arrays, a group of hard drives (minimum 3) that store data in a "stripe" accross all drives. Should one drive fail the data on it can be reproduced using parity - the difference of the drives still functioning. But that is not enough and data back-ups are placed on tapes or sent to other servers. Hard drive technology has been around since the 1970's and today it offers large capacity storage for a very low price point. Dependability has never been the hard drives strong point.

Optical discs offer a different set of challenges. Once written they can be removed from the drive. A mechanical or electrical drive failure does not present the same problem as a hard drive. Merely replace the optical drive and your existing media should be able to work with it. Also, because it is read by a laser light it should not encounter mechanical issues. The primary problem with optical media is the fact that it can be damaged through mishandling while removed from the drive, suffer environmental degradation or be missplaced. Most optical media strategies have some form of error protection built-in. But these are not fool proof and the major liability in optical media lies in that once a disc has become unreadable there is no way to disassemble it. Hard drives do offer the ability to be disassembled and the platters read in a last ditch attempt to recover data. Optical storage technology is now approaching its 30th birthday and although different strategies are employed today the underlying principles remain unchanged.

Solid state storage looks like the next technology and hopefully will offer users a stable storage environment while reducing device size, power requirements and noise while increasing speed and reliability. Hopefully the price wil eventually fall below the $/MB that we currently see in IDE hard drives today.

[lordsmurf]

Clarification -- Dye-based or pressed media is reliable. Phase-change (RW) is not. At least compared to magnetic storage methods.

Solid state is already falling fast. My current 16GB card, while not fast, was under $50. A 64GB card will be had for under $100 by year's end. Mass production would further reduce costs. People are tired of tapes and discs, they love thumb drives and camera cards. Blu-Ray was doomed while in R&D.

[bevills1]

My evidence thus far seems to indicate even DVD+RW may be more reliable than hard drive storage because I checked further to find some photo files on hard drive showed no image when selected, but same files previously backed up to DVD+RW are all still intact. I'm guessing some allocation table problems may be the culprit for hard drive corruption as suggested by oldandinthe way because I have seen Windows check disk periodically on boot and correct problems where indicated. Now I also wonder if thumb drives and other solid state storage is stable or not.

[jman98]

My evidence thus far seems to indicate even DVD+RW may be more reliable than hard drive storage because I checked further to find some photo files on hard drive showed no image when selected, but same files previously backed up to DVD+RW are all still intact.

This will not be true forever. Consider yourself lucky. DVD+RW is NOT designed for long term storage. What makes it able to be re-written means that eventually even if you do nothing, the disc will eventually develop errors because the material it uses to record data is not stable. It's this instability that makes it able to be erased and re-used.

Hard drives go bad much easier than many people realize, especially under Windows, so in your particular case the DVD+RW was still good while the hard drive was bad, but if you wait a few more years, the odds are good that the DVD+RW disc will not readable either. DVD+/-R discs use a dye for recording and this dye is designed for long term storage, so in theory good quality discs should outlast DVD+/-RW discs by decades.

[Nelson37]

Bevills, you are comparing an already defective HD against other media.

If I take a DVD and crack it in half, it's data integrity will be worse than anything else you check it against.

Multiple backups on multiple media types are the way to go.

DVD disk sensitive to high heat and humidity. Live in a flood zone, warm climate with power outages? Building completely fireproof? Disk storage in direct sunlight?

Hard drives sensitive to magnetic fields. Any powerful electric motors nearby, transformers, etc?

Each media has its own strengths and weaknesses. Backups to optical disk, supplemented with same to external hard drive, with a full set taken OFF SITE, are one way to go.

Size is also a major issue. If backup can't hold an entire drive, that means you have to pick and choose, and you had better choose wisely.

My backup horror story is the company that faithfully made two sets of accounting data on floppies, 13 of them, every day. Except about two years before I saw them, they had changed accounting programs, but never changed the backup. They were a wholesale fruit shipper, closed their doors the next day.

Backups are like closet space. There is no such thing as too many backups.

[bevills1]

In a post on another forum it was stated that NTFS drives are more stable than FAT32 due to the different way NTFS drives are scanned and fixed where required which is better than the way FAT32 is scanned and fixed. In my instance corrupt files were on FAT32 drive, and I plan to try NTFS for backup storage to see if it is more reliable. I completely agree with Nelson37 about not having too many backups which is why I keep backups on optical and magnetic media.

[Faustus]

I inscribe all my important data onto stone tablets in 1s and 0s

[piano632]

I've had data stored on CD-RW and DVD-/+RW for years which are still perfectly readable. So I must be really lucky (and most of these are using UDF packet writing). Of course, I always use good quality media and burner. I do believe phase change has one advantage over dye in that it is not light sensitive. Never had a hard drive crash or had any serious data loss either. And yes, I would say NTFS file system is superior to FAT due to better error recovery, even with power failure. But there is no foolproof storage method, always have backups of important stuff.

[themaster1]

I just read somewhere that NBC reporters use Nvodia hdd's to edit footages and use Edius software (canopus).Previously it was tape to tape.It's not for long time archival though.(i think)

I guess if you ain't rich like i am, a hdd is something to consider.

One with firewire would be a wise choice though.

[DarrellS]

I have back-up disc that are 10 years old and they're all in good shape ( -R and -RW ).

In the last four years, I've thrown away at least a half dozen Western Digital hard drives. Two things that I have learned in that time is that although they had lost integrity to be used as boot drives, they still were good for storing data and with the right software, you can get most if not all of the data off of a drive that Windows can no longer see.

Windows seems to be the biggest problem with failed drives because it decides that the drives are bad when they are not and proceeds to start erasing all of the data and it will erase all of the data if you don't hit the escape key before it deletes everything.

I kept two drives that I was going to throw away and both of those drives are system drives right now. I almost reinstalled Windows on this machine yesterday morning because of an MBR error at start up. After an hour or two of trying to fix the problem using the other PC to create start-up discs, I took the door off and wiggled the eide cable and it booted up fine.

At least half of my computer problems have been EIDE cable or Windows problems. The rest have been user error.

As for FAT vs NTFS, all of my hard drive problems have been on NTFS drives. Windows 98SE (although I had to reintall the OS at least once a year because Windows self destructed) never erased my drives without my permission.

[fritzi93]

I inscribe all my important data onto stone tablets in 1s and 0s

:P Oh man, that reminds of one of the funniest threads ever. It was a few years ago on this very subject. Cows' blood on cave walls was another nominee for most secure backup. Hey, it worked for the Cro-Magnons. The thread must not be in the database anymore, I can't find it.

[piano632]

Look at how long hieroglyphics have lasted!

[jagabo]

I inscribe all my important data onto stone tablets in 1s and 0s

Do you include parity and ECC bits?

[SCDVD]

I inscribe all my important data onto stone tablets in 1s and 0s

Sorry; that one is no good either. Acid rain will get you. Don't expect your data to last more than 6,000 or 8,000 years.

[jagabo]

Jesus, what idiot stores their stone tablet archives out in the rain? That's only appropriate for headstones.

[Faustus]

I inscribe all my important data onto stone tablets in 1s and 0s

Do you include parity and ECC bits?

Well yeah because you never know.


Also I store them in oversized comic book bags complete with acid free cardboard backing. Then put them in crates and store them in the back of an old govenment fallout shelter.

[Webster]

I inscribe all my important data onto stone tablets in 1s and 0s

Do you include parity and ECC bits?

Well yeah because you never know.


Also I store them in oversized comic book bags complete with acid free cardboard backing. Then put them in crates and store them in the back of an old govenment fallout shelter.

Ah.., but will future tecnology be backward compatible with the stone tablets? Your data may be safe, but you may not be able to retrieve them.....

[fritzi93]

I inscribe all my important data onto stone tablets in 1s and 0s

Sorry; that one is no good either. Acid rain will get you. Don't expect your data to last more than 6,000 or 8,000 years.

I'm switching to the Blu-Stone format. I'm assured it'll last at least 10,000 years.

[EDIT] Well, at least the cows' blood format "war" is over. "Plus" or "Minus"? Doesn't matter, although at one time the "Minus" media was considered more compatible. :P

[Video Head]

Double Sided - Double Density stone tablets have been available for years. We have been using them in our offices since 1998. The biggest problem we face with the DS-DD tablets is finding a writer who doesn't chisel off a thumb or finger during full back-ups.

[fritzi93]

Oh shit, I found it finally:

https://forum.videohelp.com/topic196224.html



[EDIT] As usual, Faustus was a prime instigator.

[Faustus]

hahahaha i had forgotten about that thread

[RabidDog]

Titanium rods with uridium metal inserts as Barcodes. Readable for a minimum of 200,000 probably going on for 1mil (of your Earth years). ANd stored deep underground on the moon. With some handy backups on Spectrum XL stringy Floppy's. Or as a strange geographical landmark on Mars?