Not to nitpick, but I'm going to nitpick...

Parity bits don't allow you to correct an error, only check that an error is present.

Next time nitpick in an area you know a lot about which is definitely NOT error correction or detection since you messed up the basic acronyms (not a big deal) but to say parity cannot be used for correction is flat out WRONG. The whole point of parity is to use it for error CORRECTION, here is a simple example:

Data byte 1: 0xF
Data byte 2: 0xA
Data byte 3: 0x3

Generate parity data by simply XORing each byte: 0xF XOR 0xA XOR 0x3 = 0x6

Now, if byte 2 is lost/corrupted then it can be regenerated by XORing the remaining bytes including the parity byte 0x6:

Data byte 2 = 0xF XOR 0x3 XOR 0x6 = 0xA

Viola! Data byte 2 has been 100% fully corrected using parity, so your nitpicking quote "Parity bits don't allow you to correct an error" is 100% wrong.

It is standard to pay the gas bill when you KNOW there is gas hooked up. In my case I asked the property manager to list all utilities I was responsible for on the lease and they did not list gas. Since I did not have access to the water heater and my stove/oven was electric and the heat was powered by steam I had no hints gas was hooked up.

Horizon Management was getting gas bills all year though and since they messed up and did not want a mad tenant to deal with all year they decided to not do anything until the last month I was in town in which case they signed me up for a gas account without my knowledge. I have no clue why the gas company never shut my gas off for non-payment but it may have been because the building was extremely old. I would have not been as mad if Horizon Management would have just told me the minute they realized they screwed up, or AT LEAST called me when they signed me up for the gas account. Instead I received a $300 gas bill in the mail which I had no budget for since I worked a $7/hr campus job to finish off my college career.

All I ask for is for businesses I deal with to be civil and make mistakes right. This company did neither and instead acted shadily, I guess taking advantage of young adults who have no money and are trying to better their lives by getting an education is an OK policy with Horizon Management, fits in with their "sue first, ask questions later" attitude.

I wish I could go back after them now, you are right, what they did was fraud. I had just graduated university however and was leaving town so being I had no money to pay a lawyer anyway I decided to just pay the gas bill to avoid having my credit score get killed and to just put it all behind me. This was over 5 years ago so I did not really even know much about identity theft, but it sure was that regarding signing me up for a gas account without my knowledge or consent. Thinking back I really wish I would have checked to see if the university had any programs setup to help students who have problems with landlords, I have heard about that being available at some schools. I only had enough money to get home and start looking for a job though so I ended up getting the shaft big time.

Gotta love companies like Horizon Management that prey on those with less financial and legal weight as them. Their deceitfulness ended up costing me over 1/4 of my months pay that month, all because they didn't even have a clue what utilities were actually at a property they were renting out. I paid my rent on time all nine months that school year, you would think they would have paid the bill themselves since it was their screwup or at least split the bill with me or something but nope all they care about is making their money, screw the customers.

Grumble Grumble...

Horizon Realty is a piece of shit company who sues everyone without thinking and has moldy apartments.

I hope Horizon goes out of business. I used to rent an apartment from them and when I moved in I had them clearly state in the lease what utilities I was responsible for (I mainly just wanted to know exactly what util companies I was going to need to contact and setup accounts for but also wanted to have it in writing) they wrote in pen "tenant is only responsible for electricity, cable tv, and water utilities" right on the lease. Well then at move out time I get a bill sent to me from the gas company saying I owe a whole years worth of gas bills, I was like WHAT???

Apparently the water heater was the only gas appliance in the whole apartment and since I did not have access to it and also because I had an electric stove/oven and steam heat I did not have any idea there was a gas appliance at all. Also, the gas bill sent to me was in MY NAME and I NEVER was notified any account was setup in the first place, the only way the gas company could have gotten that information was by contacting Horizon Management (and I am pretty sure setting a utility account up in someones name without them knowing is illegal but I don't know for sure).

Anyway, I contacted the manager and was told since the fine print says tenant is responsible for all individually metered utils that it was my problem, they didnt care they had written clearly I was only responsible for the 3 utils I mentioned above. It was obvious they screwed up and then when they started getting the gas bills instead of notifying me they waited until the end of the year and THEN signed me up for a gas account, this way they wouldn't have to deal with a pissed off/annoyed renter all year long and I am sure they also figured since most students leave town at the end of the year that I wouldn't have time to deal with it. The bill was only about $300 or something but I still was curious what my legal standing was so I called a friend who was a lawyer and after explaining everything he said I would probably win in court if I took it there but that would cost more than just paying the damn gas bill.

I was so pissed that a company would treat customers, especially poor college students, like that, having to pay a $300 bill out of the blue was pretty hard since my campus job only paid $7/hour. They should have just been civil and HONEST with me and after they recieved the first gas bill from the company (yes, they were getting the bills the whole year) they should have notified me that they screwed up and I would have been annoyed but it would not have been a huge deal and then I could have budgeted to pay the bill monthly. Instead I got stuck with a suprise $300 at the end of the year.

So thanks Horizon, I hope your shady business practices and sue first, ask questions later policy results in you going out of business for good. EVERYONE IN THE CHICAGO AREA STAY AWAY FROM HORIZON MANAGEMENT PROPERTIES OR YOU MAY EXPERIENCE SOMETHING SIMILAR TO WHAT I DID!

Everything I stated is true, so just try and sue me for libel you bastards.

Also you're better off looking at 1TB if you want best price per GB on the drive.

Okay, I just did that and the price dropped to about 7.5 cents per GB for the cheapest 1TB drive available on newegg.com:

http://www.newegg.com/Product/Product.aspx?Item=N82E16822145233

Yeah you write bogus comparisons and believe marketing nonsense with zero evidence and I'm the one that's the jackass. If you believe that there's nothing I can do or say thats worse than what you're doing to yourself.

You really aren't worth the time refuting. None of your arguments hold up.

Where are the bogus comparisons and explain how there is zero evidence for how the media I was referencing works? I works like using a chisel and hammer on a stone, if you cannot understand that then there is nothing I can do for you either. At least I give evidence for my claims, you make claims lacking any evidence to support them and then you disregard the evidence I have presented without explanation other than "you believe bogus marketing and write bogus comparisons and your arguments don't hold up", to argue successfully you need to support your claims by doing something like giving examples of how my claims are incorrect. Since you are uninformed and have no evidence to dispute my claims I can see why you have resorted to just saying it isn't worth your time refuting, in reality there isn't enough time for you to refute my claims since they have a lot of evidence supporting them.

Once again, since you are supposed to be so informed I would love to hear why you don't think their technology is possible and also dispute how even if it could only last 100 years how that would still make the technology less superior to long term archiving on hard drives which last 5-15 years instead. Remember this is data archiving which is writing the data to media and then storing that media somewhere for a long period of time, not incremental backups which you keep confusing with data archiving.

For your simple mind:

How is long term archiving to hard drives better than long term archiving to optical media and what part of the science of the new discs seems like fantasy? Notice I said what part of the science is faulty, not what marketing claims are faulty, there is a big difference.

That is a different situation to what most slashdotters will encounter. Most people reading slashdot will be much more interested in personal backups than computer forensics. Hard drives can work in a forensic situation too if the rules of evidence allow and if there is a well known and trusted way of transfering the data without tampering with it. Checksums on the files for example would work if stored on different media under the control of different people.

The article was regarding long term storage, so my comment regarding long term storage is relevant, talking about personal incremental backups which is usually done with hard drives is not relevant.

And yes, hard drives definitely can and are used for storing case evidence in forensic situations. But they do not work for long term archiving of data for the reasons I have already mentioned as well as for other reasons such as COST. If every legal case involving computer evidence was archived to separate hard drives the cost would be enormous relative to storing the same amount of data on optical media. You can just forget about archiving to a huge array of hard drives as well, the only way to have a true backup in that situation would be to have a 2nd huge array of drives which would further drive the cost up over an optical media solution. It also just does not make sense to pay to have the reading components attached to every media piece to put in the long term archive as well as have to deal with the problems associated when the reading components fail, this is a write once situation where files will not be edited and do not need to be accessible 24/7 so keep data and the reader SEPARATE. Here is a simple real world cost comparison:

1) The cheapest 100 pack of single layer DVD+R's from a decent brand I can find on newegg.com is:
RiData 4.7GB 16X DVD+R 100 pack is $17.99 / 470GB = 3.8 cents / GB

2) The cheapest 500GB hard drive I could find is:
Samsun HD502HI 500GB SATA 300 is $49.99 / 500GB = 9.9 cents / GB

The hard drive solution costs nearly 3 times more per GB which definitely is a significant price difference.

Also, long term archiving is not just something to be used in computer forensics, that is just one tiny usage for it. Medical, insurance, and other important records need to be stored long term as well and optical media fits the situation very nicely.

Yeah, there's the hallmark of a reliable storage medium. How often does your hard disk fail to write 10% of the data?

The point I was making was if it is known that write errors can and will occur then verification of the written data is a necessity. Once the data is written correctly then optical media can stand the test of time much better than optical media. I can take a CD made in the 80s and walk into Best Buy and play it on nearly any computer in the store. Most likely the CD/DVD drive in the computer in the store will have a SATA interface too, this is evidence that keeping the reading components separate from the media is beneficial to long term storage since the archiver does not need to worry about computer interfaces working in the future at all with optical media. What other 20+ year old media can you do the same with? That is right, none, so there is one more real world example as evidence optical media is superior for long term archival compared to hard drives.

I won't be taking your advice then. There's a conflict of interest. In any case you're just making the case AGAINST optical media.

If you want to remain ignorant and not take my advice then go for it, I won't lose any sleep. You are incorrect again though, I did not make a case against optical media, I made the case that if you are going to use optical media in a valid situation such as long term archival that you absolutely must verify the written data. Once the data is written correctly which is 99% of the time as long as good media is used then you can enjoy the benefits such as cheaper cost per GB, longer storage life, and less parts to fail compared to hard drives.

Optical media isn't without problems, I admit that, but if proper procedures are followed to combat the problems then there are many benefits to be had.

So what you're saying is that you need a reader that's no longer manufactured and is obsolete to get reliable reading? Am I suppose to be impressed? That's horrible. What happens in another 5 years when the number of working Plextors has dwindled?

Please don't resort to arguments of your credibility because you happen to work in the field. For someone that does, you've said some extremely FOOLISH things.

I never said you needed a Plextor to get reliable reading, I said for discs that HAVE PROBLEMS such as being scratched, the dye deteriorating on cheap media, etc you would be amazed that the disc you tried in 100 modern CD/DVD drives and can't be read can magically be read in an old Plextor. If you take care of the discs and don't get cheapass media then the disc should be readable in ANY drive. You keep putting words in my mouth instead of comprehending what I write out.

Regarding your comment about me saying foolish things, you only think what I say is foolish because you are ignorant to optical medias benefits to long term archiving. How about instead of making up words to put in my mouth and attacking the known writing problems optical media has you focus on making an argument against my argument that optical media costs less be GB and is more reliable long term (as long as it was written and stored properly) compared to hard drives. I will love to hear your argument regarding how keeping the reading components connected to the data storage medium is an advantage in long term data archival situations.

No danger. I don't drink.

Seriously, you're willing to believe that a DVD or CD will last 1000 years based on marketing and pseudoscience and I'm the one that looks like an uninformed jackass? Please don't make me laugh.

I think I've wasted enough time talking to someone who believes in magical digital media that lasts 1000 years. You want to know what media lasts 1000 years? Stone tablets. Even that requires proper storage. (Paper and parchment will also last but it will degrade even if stored properly)

I don't drink either.

Anyway, what I said was even if the 1000 year claim is just marketing fluff and the real longevity was only 1% of that that would be 10 years which beats most hard drive longevity right off the bat. Now, after reading the article (did you even do that?) I learned that what they are doing is completely different than what is done to write data to current optical media. Current writable optical media has dye which the drive laser can shoot to create a phase change and since the dye ages and deteriorates this means at some point the data will just be gone.

This new technology actually etches the data on a disc, you know, like using a chisel and hammer on a stone tablet (funny you gave that as an example in your argument lacking any evidence against the companies claims since you probably didn't read the article at all). This type of storage has been proven to last a long time, go check out the hieroglyphics in Egypt if you want proof. The reason current discs deteriorate is because the dye is organic, so if there was a way to do the same thing organic dye does but with an inorganic material that never deteriorates...

"Lunt and Linford found that an inorganic material similar to obsidian, a glass-like igneous rock, could be permanently bound to a reflective metal, as O'Connell explained last year to Silicon Slopes, an online tech review. This hard surface could then be etched away to record binary data."

Is that process too complicated for you to understand and/or do you not think it is possible with current technology?

I think the process is braindead simple to understand (hold your two hands up in front of your face and in front of a window on a sunny day with the sun beating in and then remove one hand and that is basically what etching away the material in front of the reflector, your face, is like) and I have no reason to believe binding a material to polycarbonate or whatever is used would cause major problems.

Therefore I think this new technology might really turn out to be something useful. I don't base this on marketing and pseudoscience, I base it on taking the time to understand the technology involved. I need to see more evidence that what they claim to be doing is really possible but my guess is that if Philips ends up licensing the technology (which they are about to do) that that is all the proof I need that is really can be done.

Do I believe the claim of 1000 years? Not without more evidence, I want to know what adhesives could last that long and also how polycarbonate and other materials could last that long without deterioration. Even then I would have a hard time believing 1000 years. With current technology however and using an inorganic medium to put in front of the reflector to be etched away I could see at least 100+ years being a real possibility. I look forward to checking this new technology out, if it turns out to really not be all BS then it could have a huge impact on long term data archiving.

You look like an uninformed jackass because you are one. Do some research and then dispute my claims without putting words in my mouth or talk about unrelevant matters. All I am saying is that the technology seems feasible for the reasons I described earlier. As you have seen I did NOT base those claims solely on marketing or "pseudo-science" as you claim. Since you are supposed to be so informed I would love to hear why you don't think their technology is possible and also dispute how even if it could only last 100 years how that would still make the technology less superior to long term archiving on hard drives which last 5-15 years instead. Remember this is data archiving which is writing the data to media and then storing that media somewhere for a long period of time, not incremental backups which you keep confusing with data archiving.

isn't that part of the problem with optical media? Every trip from storage to the reader is an opportunity for damage to occur. At least a hard drive's disk is kept safely in a metal box away from humans.

Sure, that is a problem but processes can be put in place to keep the risk of damage low, it isn't very difficult to handle optical media correctly and carefully. One solution would be to just use DVD-RAM discs which can be bought in protective catridges which prevent the disc surface from being touched and should prevent contamination/damage except brute force or U/V damage.

As I pointed out before the problem with a hard drive compared to optical media for long term archiving is a HD contains many parts that can fail since it contains all of the data reading components too. This means if you come back to the data archive in 20 years you run the risk of all the complicated internal parts having a failure and you also may not have a way to hook up a SATA drive at all anyway. With optical media all you have to fail is the polycarbonate and the materials storing the data on the disc.

So you see by using optical media for long term archival you just have to check the discs however many years you wish to make sure the data is still readable and you just have to make sure to keep a drive around that can read optical discs and as new I/O interfaces come about the manufacturers will convert the new optical drives to have the new I/O interfaces. After 25 years with a hard drive you would not only have to worry about the reading components in the drive still working correctly but you also would need to make sure you always have a way to connect whatever 25 year old interface is on the hard drive to a new computer. Of course you could just keep old components around but that just adds more cost and extra work compared to the optical media option.

For those concerned optical media is going anywhere anytime soon I don't think so, there are just too many situations it is the cheapest and easiest media to use (want to send grandma and your parents and your siblings who live 100's of miles away your gigabytes of vacation photos and videos then make a DVD you can easily and cheaply mail and can be viewed on a DVD player or computer, etc). Optical media is also the most abundant form of computer media in the world so there will be a demand for optical drives for a long time. Another thing is all optical drives are made to be backwards compatible with older types of media too which is a huge benefit.

Consider this, I could go get a copy of the first audio CD ever released (happens to be an "ABBA: The Visitors", I had to look it up) which was released 25 years ago and I could walk into Best Buy or any electronics store and play the CD back on most likely any computer in the store. What other 25 year old media could that be done with?

Your practice with hard drives is anecdotal evidence and nearly anyone I know (more anecdotal evidence) who works with a lot of hard drives knows they fail quite often, you just have been lucky. A big push for RAID 6 was to help combat the huge problem of increased hard drive failures, especially with SATA drives which have a smaller average MTBF then the IDE drives they are replacing (anyone serious about reliability should be using SAS or Fibre Channel though), so my anecdotal evidence actually has facts backing it up. Using the new SATA drives results in the chance of a two disc failure being pretty high which many people realized meant RAID 5 would not be good enough anymore and so RAID 6 was created.

Yes, for incremental backups optical media would not be a good choice due to the time involved creating the set of discs, my whole comment was focused on long term data archival which is done once however. I just wrote another comment where I gave the example of a computer crime case where all of the evidence would need to be archived because it MUST be available in the future in case it is needed but most likely the data will never be touched again, that is where optical media beats hard drives. If the files do not need to be quickly accessible since they will not be accessed often then I don't see a downside and in fact see many benefits to keeping the files on good quality optical media (and not have the only copy of a file exist on a single disc not protected by some kind of EDC/ECC) compared to a hard drive. For "backing up" an MP3/movie collection your method would be great since you probably want access to those files somewhat often, if personal pictures are involved however then archiving to optical media seems like the best choice to me since it is more reliable long term and I only have to mess with the files once to get them on the discs and then just check the discs out every few years to see if a new archive needs to be made due to disc problems.

As for optical media failures: I've had _a lot_. Sure, I never used archival quality media or a top-of-the-line burner, but I hardly think that most people who backed up their family photos on CDs or DVDs use archival media or top-of-the-line burners... Hard drive failures? Not so much. In ten years or so, one failure (so about one out of thirty), which is OK if you're aware of it and use some sort of backup scheme or RAID1 to protect against mechanical failure.

I work with optical media every day at my job so I have definitely seen a lot of media failures too, but there are many things that can be done to alleviate those problems. The change that I think would eliminate a huge majority of the problems people experience would just be to turn on verification of files after burning. Sure, this requires all of the file data to be read back from the disc and takes a while but you would be crazy not to do this check with a disc containing important files.

If the disc was entirely written correctly in the first place then I would say how/where the media is stored is the next most important component (other than if the media is decent quality). A cool, dark place would be the best, and immediatly taking the newly burned disc out of the drive and placing it in a holder to prevent the disc surfaces from being touched would be ideal.

Another tip is to write on the holder/case for the disc, do not write directly on the disc if it is a backup/archive copy even with a "disc safe" pen. This is especially true if the disc is a CD which does not have the piece of polycarbonate on top of the disc reflector like a DVD which has the reflector sandwiched between two pieces of polycarbonate (this makes the top of CD's the most likely part to get damaged, the reflector can easily be chipped off and when you lose the reflector the dye encoding the data goes with it so it is impossible to recover the data where the reflector peeled off).

With that said doing incremental backups to hard drives for personal files is not a bad solution for many types of files, it makes the process go much quicker than using optical media and as long as multiple drives with the same data or some other backup scheme is used it should work alright. I think you are lucky to have only had 1 hard disk failure in 10 years and 30 drives and with the even shorter life spans for SATA drives I expect you will be seeing quite a few more failures. I personally have had about 4 out of 9 hard drives fail over the last 9 years (and even more if I count the drives that have failed at the small company I have worked at the last ~5.5 years) so I have the opposite experience as you. Our experiences are anecdotal however so they don't mean much, what does mean something is how current SATA drives have a MTBF of under 6 years, which IMO is pretty crappy for a hard drive.

Personal backups which you are describing are NOT the same as long term data archiving which is what I was talking about. Long term data archiving is for situations where you do not need access to the data often but you MUST be able to access the data when the time comes in the future. A perfect example would be the need to archive all of the evidence from a computer crime case, once the case is over with a copy of the evidence will definitely need to be kept around IN CASE it is needed in the future, in this situation you want the data to be on media that is reliable long term and also cost effective both of which hard drives ARE NOT in relation to optical media. This type of situation would also be a perfect to use a robotic loader to take care of burning off the discs for the case, so creating all the discs can be very pain free as well.

I can definitely see consumers needing long term archives too such as for personal pictures and videos, so long term archiving is not just for some business situations. Personally I would rather burn off sets of good quality DVD's to backup my pictures/videos/other important files and then store multiple copies of the sets in different locations rather than having to rebackup the same data to multiple hard drives all the time. Archiving is for files that do not need to be accessible quickly and for files that the originals should not be edited, if the file data is not going to change then why waste time constantly re-writing the files and/or checking them for problems? By archiving you eliminate that inefficiency and also will not need to check out the archive for problems as often as would need to be done when backing up to hard drives where all the file data could be corrupted/overwritten quickly since it is NOT write once.

Sure, for backing up personal files using a few hard drives with redundant data works and is MUCH easier than backing up to optical media if a large amount of data is involved, but that isn't long term data archival which is what the whole topic is about.

I wouldn't trust your data to a single DVD or CD either.

I never said a single piece of media could be trusted to store data, any backup/archive would need at least something extra protecting the data either just extra copies or ECC/EDC that is stored on separate pieces of media. I would however trust my data to still be accessible on quality DVD media 10 years after the disc was created while I would not expect a SATA hard drive to work after 10 years especially since most SATA drives have an MTBF of under 6 years. 6 years or even the 15 that a lot of SAS/Fibre Channel drives claim is just NOT suitable for long term archiving of large amounts of data. No matter what the MTBF is the simple fact is HD's were not designed to sit and not be turned on for long periods of time, if they sit long enough I know at least with older hard drives the result can be the read heads sticking to the data platters they are sitting on when not spinning (another example of why keeping the reading components separate from the data storage mechanism is the right approach for long term archival).

What rubbish! If your disk is damaged, a better or different reader only has a small chance of saving it.

You didn't read what I wrote closely, I never said the disc was damaged, I said what happens if the reading part of an optical drive fails compared to a hard drive. With a hard drive you have to send the drive off to get hardware replaced (unless you were smart and did not keep the only copy of files on the disk) while with an optical disc you can just put the disc in another CD/DVD drive and you can access the data.

Also, you would be very suprised what a different reader is able to do for the readablility of a disc, especially a good old reader compared to ANY CD/DVD drive being sold today. I have personally seen and heard of many, many situations where a corruped CD (dye problems, scratches, etc) cannot be read in many different CD/DVD drives but if it is put in an old Plextor 12-10-32 drive it can be read NO PROBLEM. I work in this field, from your comment I take it you do not, so don't speak about that which you do not know.

10% failure every few years is hardly what I'd call a good long term storage option. I think you've got blinders on.

I would bet that most of the discs in that 10% figure were never written correctly in the first place. You can't blame the media when the data written to the disc was not verified after it was written. I work at a company that focuses on forensic as well as data recovery software for optical media and I have come across numerous examples where the data was just not written correctly in the first place or at all. One extremely popular CD/DVD burning application used to have the problem where an error would occur but the user would be told the disc was written fine while only the file system was written and maybe a little bit of file data. Many people "check" the discs they write by opening up a file manager and seeing if the files they wanted on the disc are listed and that is all, they don't actually try opening the files and when this is done all the files show up fine (since the file system was written correctly) but they don't figure out the files have a problem until months/years later when they go back to the disc and realize they can't access all the files. This situation is the worst since there is NOTHING to recover since the data was never written in the first place.

So, I would be interested to see a comparison made where all the discs had been verified after being written, I would bet that 10% failure amount would drop an order of magnitude as long as quality media was used. How/where the discs are stored can have a big impact on longevity as well.

Just how many affordable (cheaper than multiple hard disk) robotic DVD storage systems have you seen?

People doing real long term data archival don't care what it costs, but I will say that there is a wide range of prices starting from around $1000 up to $50,000+. This is out of the reach of most consumers but in their situations the stuff they would really be archiving (and not just making a backup that is easily accessible) could probably fit on a bunch of DVD's which shouldn't take too long to create manually.

Copy to multiple hard disks. Refresh the disks every few years.

People archiving data DO NOT want to have to keep moving the data to new media "every few years". Once again you are confused between backups and long term archiving.

There are also claims of Santa Claus and the Tooth Fairy and Elvis being abducted by aliens. Don't believe all the claims you read, especially when someone can profit by lying to you.

I never said I believed anything about the 1000 year claim at all, that is why I said "there exists media with claims of 1000 year life" and not "there exists media with 1000 year life". Based on what I have learned about the technology (it doesn't just change some dyes optic properties, it actually etches the data on the disc) I would say it definitely sounds feasible for it to last a very long time, and even if it ends up really only lasting 1% of the claimed amount that is 10 years which is still better than most hard drives can be reliably trusted to hold data, especially consumer level hard drives. All indications show it to be superior to using a hard drive.

You're smoking too much pot.

You are the one smoking too much (or maybe you were drunk at the time), you don't even know the difference between personal "backups" and long term data archival. Backups can be done by making multiple copies of data on multiple HD's but long term archiving of data that way would be less reliable than using optical media (due to more pieces on a HD that can have problems) and would be less efficient since optical media is relatively cheaper since every piece of optical media does not contain all the reading components needed to access the data.

I would love to do a test where I would go and buy 5 hard drives, put the same 4.7GB of files on each one (for test simplicity) and then write out 5 high quality DVD+R's with the same 4.7GB's of data on each (and of course have the data verified after being written) and then put all 10 pieces into a vault for 10 years. If the drives even spun up after sitting for 10 years I would be impressed and I would wager that the DVD's would have none or at least less problems than the HD's. I guarantee in 10 years I will be able to easily find a DVD drive with a current computer interface that can read a DVD+R, I would not be so confident that the SATA or whatever HD interface will still be around however, so just accessing the data on a HD could be difficult after a long period of time due to the I/O connection involved.

Go back to your beer now or else you might sober up and become angry that you made yourself look like an uninformed jackass.

I'm almost sure that companies aren't following the CD-R/CD specs.

The companies manufacturing CD/DVD drives these days are definitely not doing anything extra in that department.

As an example, a few years ago I noticed that all the Pioneer drives I have at the office (around 10 different models) returned bogus data for sectors on a disc that ARE NOT READABLE. You see on a packet written CD there are "packet gaps" which is a few sectors at the end of packet written data and the gap is the sectors hit when the laser is turning off. Every drive but the Pioneer drives I have correctly return a read error while the Pioneer drives returns a sector full of bogus data when attempting to read these sectors.

The worst part is that re-reading the same sector in a packet gap results in completely different data being returned with every re-read, so the bogus data isn't even consistent. This raises major issues when making forensically sound optical media images and my attempts to get Pioneer to at least fix the problem via firmware updates for their current drives have all failed and I was left being told an engineer in Japan may be contacting me (2 years later still no response). Our response with our optical media forensic software was to check if a Pioneer drive is being used for an examination and if so to let the user know that the drive is not one that should be used for forensic purposes.

Yes, the failure chance is smaller for a hard drive that is not powered up all the time compared to one that is powered up all the time but that still does not overcome the simple fact that hard drives just have more parts that CAN fail to begin or be incompatible with (such as communication interface) compared to optical media. With optical media the reading mechanism is separate from the media the data is stored on which means if part of the reading mechanism fails the disc can easily be removed and put in another reader drive to access the data. If you get a hardware failure with a hard drive you will be paying big bucks to get your data back, it is not trivial to do the work involved and the process requires specialized tools and expensive things like clean rooms.

For long term archival storage there is absolutely no reason to make the media attached to the reading mechanism like a hard drive, it just adds unneeded extra potential failure points and that is just one reason optical media is superior.

Yes, older Plextor drives are great for reading discs that other readers have problems with. I work at a company specializing in forensic software for optical media and we recommend the older Plextors to our customers and we always have a stockpile at our office. The older Plextor drives were built with much better optics and other components compared to the cheap stuff drives are made of today which is a major reason they read discs better. However, current Plextor drives are all rebadged drives from other manufacturers so I don't recommend those.

Other than those two uses I can't think of a good use for DVD/CD. Certainly not archival storage.

Are you serious? You believe hard drives qualify to use for archival storage? Short term okay, but definitely not long term, especially with SATA drives which have extremely high failure rates. Have you ever had a HD with the only copy of important data have a hardware failure such as the controller board or a motor going out? If not then I can tell you that it will cost a huge amount of money to send it to a company for recovery, compare that to putting an optical disc in a drive that suffers a hardware failure, with the optical media you just have to put the disc into another drive and boom you have access to the data again.

For long term storage however I think it is hard to beat optical media. Robotic systems exist for archiving large amounts of data so that is not a problem and blu-ray discs are coming down in price and hold pretty large amounts of data, the reading mechanism is kept separate compared to a HD which has many internal parts which can fail so it is more reliable long term, and there exists media with claims of 1000 year life which is untouchable for HD's. For real data archival no one even considers hard drives, that would be insane, optical media however is a real alternative along with tape, but I think optical media is superior.

First, for what it's worth I work as a developer in the CD/DVD forensic software world so I know quite a bit about CD/DVD media and as the AC above me posted your claim that ripping to an ISO will work just fine with any DVD is NOT the case with any DVD with CSS or other protection because the encryption keys are stored on the disc in an area that is not copied when just reading off the user data from the disc. If the video on the disc is encrypted at all (and nearly all commercial movies these days are, years ago it was somewhat common to come across discs with absolutely no protection though) then you may be able to rip the video to the hard drive but "normal" DVD playing software will NOT be able to play it since there is encrypted video present and there is no access to the encryption keys. The proper thing to do would be to decrypt all of the video file data while making the ISO image (would require special software) and these days just doing that would still not work in most situations due to other types of copy protection which would require reauthoring the DVD pretty much.

Also, in order to make an ISO image and read protected sectors from a DVD in the first place the drive would have to be tricked into allowing read access to the protected sectors (otherwise read attempts will result in failure "READ OF SCRAMBLED SECTOR WITHOUT AUTHENTICATION"), so just unlocking the drive to allow reading protected sectors is most likely illegal as well since it would be bypassing a form of copy protection without permission.