Is DVD an reliable option for video storage?

[Kerry56]

I think people underestimate the length of time a good dvd-r can be used as storage.
If you use good media, burn at a moderate speed, and store them properly, dvds work pretty well as one part of your backup strategy.

How do you suggest to store them properly? Placing them in their original spindle at room temperature and without touching them is enough, right?
I read somewhere that placing the discs vertically rather than horizontally helps acheive a longer life. Is it true?

DVD's generally have hub rings which keep them from rubbing against one another in spindles. So you can store them in spindles if you wish. Over time there is the possibility that gravity will cause them to droop slightly, and thus lose a bit of flatness, which can cause them to be harder to read. I've never heard how long this will take, and I've never seen it myself, but it is the reason why many people advise storing them on edge in individual cases or individual hanging sleeves .

If you live in a humid climate, you might want to seal them and put in a small bag or two of dessicant to absorb moisture from the air.

And you can certainly store your mkv files as data on dvds, and not lose any quality.

[deadrats]

great, another one, "gravity will cause dvd's to droop over time and cause them to lose a bit of flatness, albeit slightly".

does anyone else have any "brilliant" little tidbits they would like to add with regards to dvd's?

[Kerry56]

You left out "the possibility of." As stated, dumbbutt, I've never seen it happen, but this is the reasoning behind storing on edge.

Edit: And my own feeling is this is more theoretical than any real threat. Its much more likely to warp them through excessive heat or jamming them together in cd/dvd binders.

[orsetto]

are you on drugs? i'm being serious, do you engage in recreational drug use? regardless of whether the answer is yes or no i strongly recommend you get help and fast, you are a very sick individual.

wow, one has to wonder what is jiggling in someone's head for them to believe that a HDD used as backup, i.e. only operational during the backup process, you suffer from "unpredictable data corruption" due to cosmic rays, the earth's magnetic field, random luck, etc.

that's just too damn funny, not to mention sad that the poster is actually being serious.

Don't be an ass. You know damned well I was using those "reasons" to make a point about the danger of relying only on a single HDD for file backup. Lighten the fk up.

My point was you have tons of people out there who think just dumping their collection of DiVX downloads into a cheap Western Digital Passport HDD, and storing that HDD in a desk drawer for years on end, is a perfect archiving strategy. It isn't: hard drives were never infallible long-term, and they're much worse today now they've become consumer commodity items with disposable pricing. So its a good idea to spread the risk around, with backups to portable HDD, standard-size HDD, and some optical format. One bit of HDD corruption in the wrong sector, and all the data is lost unless you want to spend a fortune at a recovery service. Corruption to an optical disc, you just lose the data on that disc, while the others may still be OK. HDD can fill in for failed optical discs, and vice versa. Every few years, make new backups on other media or devices: in ten years time, there may be much better archiving possibilities than we have now.

[Cornucopia]

Well said, orsetto. I agree with you completely. Diversify to spread the risk around, and have a plan of cyclical data migration.

BTW, maybe deadrats forgot both science and history, but for those not knowing: LPs use PVC, CD/DVD/BD use Polycarbonate. Both are polymers (aka PLASTIC) which BY NATURE are fluid (depending upon their temperature). Just like where evaporation can occur at ANY temperature, but occurs more and more the higher the temp goes, the possibility of polymers "puddling" becomes more and more with higher temps, yet is still possible even at room temps (just takes longer). And anyone who has had a record collection for over 20 years can bear witness to LPs bending & puddling. CD/DVD/BDs can do the same, it just takes DECADES instead of YEARS. The problem for them of course, is that even SMALL amounts of warpage can majorly screw up their error correction capabilities. So it's not some stupid "tidbit". Look it up.

Scott

[deadrats]

BTW, maybe deadrats forgot both science and history, but for those not knowing: LPs use PVC, CD/DVD/BD use Polycarbonate. Both are polymers (aka PLASTIC) which BY NATURE are fluid (depending upon their temperature). Just like where evaporation can occur at ANY temperature, but occurs more and more the higher the temp goes, the possibility of polymers "puddling" becomes more and more with higher temps, yet is still possible even at room temps (just takes longer). And anyone who has had a record collection for over 20 years can bear witness to LPs bending & puddling. CD/DVD/BDs can do the same, it just takes DECADES instead of YEARS. The problem for them of course, is that even SMALL amounts of warpage can majorly screw up their error correction capabilities. So it's not some stupid "tidbit". Look it up.

really, you felt the need to give me a physics lesson? in case you weren't paying attention the 93 thousand or so times i have mentioned this i was a physics and comp sci major in college.

allow me to point out a few things: it's contradictory to say that a substance is a fluid by nature and in the same breath say that said fluidity depends on the temperature.

furthermore, your little rant only makes the case against using optical media for backup, not for.

records, as you pointed out, will bend and warp but the reason is only partially ambient heat energy. people tended to improperly store records, either in basements, sometimes close to the furnace room and quite often in poorly ventilated attics, where temperatures can soar to 120 degrees in summer months. but that's not what causes the warping, heat energy can only cause structural weakness you still need a force to cause the bending.

this force was not gravity, rather it was the angular momentum caused by the spinning of the record on the record player coupled with the pressure exerted on the record by the record player arm; in fact even if you kept the records in a perfectly climate controlled room the 2 above forces would eventually warp the record.

dvd's are not susceptible to drooping at rest, in a spindle separated by spacers because they are in an inertial resting state and they are not subject to drooping or warping during usage because they have a short moment of inertia and they don't have a perpendicularly applied force on the surface of the disc.

harddisks, also have short moments of inertia and likewise don't have any perpendicular facing forces applied to them (the spindles inside a hard drive don't actually touch the platters).

but what i found most humorous was the notion that a generalized gravity field or magnetic field (i.e. the earth's) would have a deteriorating effect on a localized field (the hard drives) or that cosmic radiation, most of which is filtered out by the earth's various layers of the atmosphere and earth's magnetic field would somehow result in data corruption within a hard drive. and let's not forget the thought that somehow a plastic disc, at rest, supported by a spacer, with a moment of inertia less than 3 inches from the edge of said spacer, would somehow experience sufficient torque at the outer edges from gravity and spline differences alone, to actually cause drooping, thus rendering the disc useless and the data corrupt.

i mean really?

[_Al_]

physicist present, it got to this point of discussing physics,..., will emp destroy HDD or discs or thumbdrive or tape ? Or better, what is better storage in this case. I know Faraday cage etc, but what is better ...

[TimA-C]

deadrats, do people call you "Sheldon" by any chance?

[harishkumar09]

physicist present, it got to this point of discussing physics,..., will emp destroy HDD or discs or thumbdrive or tape ? Or better, what is better storage in this case. I know Faraday cage etc, but what is better ...

Actually given that I live in Bangalore, India, and given the tensions between Indian and Pakistan and the fact that there are plenty of Mad Jihadis out there, and Bangalore being a favourite target of the said nut-cases, there is a greater danger of my HDD/DVD data getting corrupted due to EMP than myself accidentally dropping them on the floor!

So, I would really like an answer to _Al_'s question.

[loster]

Well said, orsetto. I agree with you completely. Diversify to spread the risk around, and have a plan of cyclical data migration.

BTW, maybe deadrats forgot both science and history, but for those not knowing: LPs use PVC, CD/DVD/BD use Polycarbonate. Both are polymers (aka PLASTIC) which BY NATURE are fluid (depending upon their temperature). Just like where evaporation can occur at ANY temperature, but occurs more and more the higher the temp goes, the possibility of polymers "puddling" becomes more and more with higher temps, yet is still possible even at room temps (just takes longer). And anyone who has had a record collection for over 20 years can bear witness to LPs bending & puddling. CD/DVD/BDs can do the same, it just takes DECADES instead of YEARS. The problem for them of course, is that even SMALL amounts of warpage can majorly screw up their error correction capabilities. So it's not some stupid "tidbit". Look it up.

Scott

The polymers discussed are not fluid at room temperature they may exhibit behavior that is like a fluid, but fluids cannot support shear forces. Polymer exhibit viscoelastic behavior. Polymers undergo creep http://en.wikipedia.org/wiki/Creep_%28deformation%29. Deforming permanently at elevated temperature and/or high loads. This depends on the specific polymer and the additives.

[deadrats]

deadrats, do people call you "Sheldon" by any chance?

LOL, i had a good friend of mine who was a huge fan of "the big bang theory" and she did call me "sheldon" sarcastically a few times.

[Cornucopia]

BTW, maybe deadrats forgot both science and history, but for those not knowing: LPs use PVC, CD/DVD/BD use Polycarbonate. Both are polymers (aka PLASTIC) which BY NATURE are fluid (depending upon their temperature). Just like where evaporation can occur at ANY temperature, but occurs more and more the higher the temp goes, the possibility of polymers "puddling" becomes more and more with higher temps, yet is still possible even at room temps (just takes longer). And anyone who has had a record collection for over 20 years can bear witness to LPs bending & puddling. CD/DVD/BDs can do the same, it just takes DECADES instead of YEARS. The problem for them of course, is that even SMALL amounts of warpage can majorly screw up their error correction capabilities. So it's not some stupid "tidbit". Look it up.

really, you felt the need to give me a physics lesson? in case you weren't paying attention the 93 thousand or so times i have mentioned this i was a physics and comp sci major in college.

allow me to point out a few things: it's contradictory to say that a substance is a fluid by nature and in the same breath say that said fluidity depends on the temperature.

furthermore, your little rant only makes the case against using optical media for backup, not for.

records, as you pointed out, will bend and warp but the reason is only partially ambient heat energy. people tended to improperly store records, either in basements, sometimes close to the furnace room and quite often in poorly ventilated attics, where temperatures can soar to 120 degrees in summer months. but that's not what causes the warping, heat energy can only cause structural weakness you still need a force to cause the bending.

this force was not gravity, rather it was the angular momentum caused by the spinning of the record on the record player coupled with the pressure exerted on the record by the record player arm; in fact even if you kept the records in a perfectly climate controlled room the 2 above forces would eventually warp the record.

dvd's are not susceptible to drooping at rest, in a spindle separated by spacers because they are in an inertial resting state and they are not subject to drooping or warping during usage because they have a short moment of inertia and they don't have a perpendicularly applied force on the surface of the disc.

harddisks, also have short moments of inertia and likewise don't have any perpendicular facing forces applied to them (the spindles inside a hard drive don't actually touch the platters).

but what i found most humorous was the notion that a generalized gravity field or magnetic field (i.e. the earth's) would have a deteriorating effect on a localized field (the hard drives) or that cosmic radiation, most of which is filtered out by the earth's various layers of the atmosphere and earth's magnetic field would somehow result in data corruption within a hard drive. and let's not forget the thought that somehow a plastic disc, at rest, supported by a spacer, with a moment of inertia less than 3 inches from the edge of said spacer, would somehow experience sufficient torque at the outer edges from gravity and spline differences alone, to actually cause drooping, thus rendering the disc useless and the data corrupt.

i mean really?

You may have been a physics major, but you weren't a chemistry or chem-e major. My dad was (actually a long time chem-e researcher at a major international chemical corporation, and I ran this past him).

Yes, poymer-based media will droop with age, depending upon storage conditions.
No, it is NOT contradictory about fluid properties. Hell, WATER is fluid at some temperatures and not at others.
Yes, that means they aren't the perfect backup medium. I had said that previously. However, NOTHING is.

You arguments about "no external force acting on the platters" forgets GRAVITY, which is a perpendicular force on the platter. Not a lot, but enough to make a difference over time. Spinning platters counteract this because of centrifugal force. Platters at rest (aka in storage) do not have this to counteract. Record arm bend pressure is counteracted by the turntable (though there is groove deformation).

And your "rant" about magnetic domains remaining intact is not borne out by either the scientific literature or practical experience.

Yes, REALLY.

And you seem to be forgetting that the whole point of orsetto's and my suggestions were to say that one should not put all of one's eggs in one basket. Knowing that particular media is/are fallible only affirms & re-inforces that premise, not debunks it.

@ _AL_,
Regarding EMP vs. HDD/Flashdrives? Don't know, yeah probably not good at all. Chances of that happening? Too small to worry about (or you have other, more important things to worry about at that point).

Back OT, yes, High quality DVDs are fairly reliable, but no media is totally reliable LONG TERM, so you must "Data Migrate" periodically. And diversify (both medium type and location) and be redundant (multiple copies), for best data longevity. Oh, and make sure whatever format they are saved in will be accessible down the road (codec, container, filesystem, etc).

Scott

[deadrats]

physicist present, it got to this point of discussing physics,..., will emp destroy HDD or discs or thumbdrive or tape ? Or better, what is better storage in this case. I know Faraday cage etc, but what is better ...

i honestly don't see a scenario where an electro magnetic pulse would destroy the data on a dvd or on any storage medium that is not powered at the moment of the pulse; in other words i can accept the notion that a really high powered EMP would play havoc with an SSD or a HDD while powered in a running computer and especially during a read/write operation but when the device is not powered? it's absurd to think such a thing.

the localized forces present on the storage medium, i.e. the strong/weak nuclear force and the electromagnetic field would have to be over-powered by a generalized field, if that was the case then the earth's magnetic field would make any sort of e-m based storage medium impossible.

here's a more practical example, MRI machines. MRI machines have extremely powerful e-m fields, they work by aligning the protons within the hydrogen atoms found in your body, keep in mind that hydrogen is usually bonded to another element, such as oxygen, in the form of water, or in an acid base or other organic compound, so the magnetic field generated by an MRI machine is powerful enough to overcome the localized forces acting upon all hydrogen atoms, that are bonded mind you, in your body to actually change the orientation of the protons within said hydrogen atoms, and yet these machines are computer controlled, hell there's a computer built into the machine itself and even such a powerful e-m field, in such close proximity to the storage mediums are incapable of erasing the data in the rom, ram and permanent storage mediums, so we're supposed to believe that an e-m pulse originating from God knows how far away will somehow erase all data on all optical storage mediums and hard drives in a given radius? come on.

i would think that it would require a pulse so powerful that it would be lethal to all living organisms, thus rendering it a moot point as to whether or not our porn collection survived.

[_Al_]

Good to know, thanks, so theoretically it can fry only some electronic board that is actually powered up or running. Even if it disables HDD while running, discs could be theoretically removed and data read somewhere else. Tapes are safe. Optical discs are safe. Flash drives are safe (while not in use or connected). Something like that?

[deadrats]

Good to know, thanks, so theoretically it can fry only some electronic board that is actually powered up or running. Even if it disables HDD while running, discs could be theoretically removed and data read somewhere else. Tapes are safe. Optical discs are safe. Flash drives are safe (while not in use or connected). Something like that?

basically, it's really easy to put the theory to the test; pick up a cheap dvd+r or a cheap thumb drive and write some data to it, then place a large powerful magnet right next to the dvd or thumb drive and see if the data is erased, you can build a pretty powerful electromagnet yourself for a few bucks with supplies from the local hardware store.

consider this, if you buy an emf meter and check your house you will find electromagnetic fields all over the house, particularly right next to the electric box, take a dvd and hold it right next to the electric box and see if the dvd is still readable.

i'm sure you can guess that it will be.