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Helpful answers
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Mar 8, 2014 12:49 PM in response to ThomasB2010by PlotinusVeritas,ThomasB2010 wrote:
Of course some will argue you'ld have to be crazy to not have a backup, period, but face the facts, some people don't do it.Absolutely 100% without question or doubt, yes, that is 100% "crazy"
That "some people do it" is no argument for anything in life, obviously, since "some people" do the most insane things imaginable.
Hard drives are cheap as dirt, anyone lacking a minimum of 2 copies OFF-computer is making a Titanic mistake.
As for the other statements about SSD :
SSD have plenty of their own serious concerns though no moving parts.
SSDs Have Bleak Future, Says Researchers
http://www.tomshardware.com/news/NAND-Flash-SSD-MLC-TLC-Laura-Grupp,14728.html
Why Flash Drive Density Will Stop Growing Next Year
SSD are also fast approaching theoretical ultimate limits of densities, meaning the steel ceiling they cannot break thru.
also data recovery off a SSD is a pure nightmare.
Avoid SSDs for important files, says data recovery firm
http://www.pcpro.co.uk/news/385498/avoid-ssds-for-important-files-says-data-reco very-firm
contrary to views a few years ago about hard drives dying out, just the opposite has happened, people storing TONS of data is way up, and SSD in no way whatsoever can handle any of that.
too small in GB
too expensive
You can go here to stay up to date:
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Mar 8, 2014 12:48 PM in response to HuntsMan75by PlotinusVeritas,HuntsMan75 wrote:
Do you have a link to the article you got that from or maybe even some other studies or reports comparing brands and/or models?
Thanks.
an intelligent, simplex good video ,...everyone should certainly see this video on HD
http://www.youtube.com/watch?v=Wiy_eHdj8kg
The only inaccuracy in the video is at 1:47 where he says the magnets arent sensitive to temp.
Well, thats wrong, neodymium iron boron ceramic perm. magnets definitely ARE sensitive and degraded from temperature, however theyre high temps not really seen in any computer
http://blog.backblaze.com/2014/01/21/what-hard-drive-should-i-buy/
http://blog.backblaze.com/2013/11/12/how-long-do-disk-drives-last/
Hard Drive Warning (all makes and models)
Ironically but logical, new hard drives are far more fragile than one that has been working for several months or a couple years. So beware in your thinking that a new hard drive translates into “extremely reliable”!
Hard drives suffer from high rates of what has been termed "infant mortality". Essentially this means new drives have their highest likelihood of failing in the first few months of usage. This is because of very minor manufacturing defects or HD platter balancing, or head and armature geometry being less than perfect; and this is not immediately obvious and can quickly manifest itself once the drive is put to work.
Hard drives that survive the first few months of use without failing are likely to remain healthy for a number of years.
Generally HD are highly prone to death or corruption for a few months, then work fine for a few years, then spike in mortality starting at 3-4 years and certainly should be considered end-of-life at 5-7+ years even if still working well. Drives written to once and stored away have the highest risk of data corruption due to not being read/written to on a regular basis. Rotate older working HD into low-risk use.
The implication of this is that you should not trust a new hard drive completely (really never completely!) until it has been working perfectly for several months.
Given the second law of thermodynamics, any and all current mfg. HD will, under perfect storage conditions tend themselves to depolarization and a point will be reached, even if the HD mechanism is perfect, that the ferromagnetic read/write surface of the platter inside the HD will entropy to the point of no viable return for data extraction. HD life varies, but barring mechanical failure, 3-8 years typically.
Hard drive failure and handling
The air cushion of air between the platter surface and the head is microscopic, as small as 3 nanometers, meaning bumps, jarring while in operation can cause head crash, scraping off magnetic particles causing internal havoc to the write surface and throwing particles thru the hard drive.
Hard drives are fragile in general, regardless, ... in specific while running hard drives are extremely fragile.
PDF: Bare hard drive handling generic instructions
hard drive moving parts
Some of the common reasons for hard drives to fail:
Infant mortality (due to mfg. defect / build tolerances)
Bad parking (head impact)
Sudden impact /head crash (hard drive jarred during operation, heads can bounce)
Electrical surge (fries the controller board, possibly also causing heads to write the wrong data)
Bearing / Motor failure (spindle bearings or motors wear during any and all use, eventually leading to HD failure)
Board failure (controller board failure on bottom of HD)
Bad Sectors (magnetic areas of the platter may become faulty)
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Mar 9, 2014 12:07 PM in response to PlotinusVeritasby R.K.Orion,This might be a little off topic for this thread, but the storage in an iPhone .... is that an SSD? Does it have a controller? Is it just flash memory? Do bad blocks map out of iPhone storage space?
I put up a post in the iPhone section about this but several in this thread seem to know a lot about storage. I always figured the iPhone was basically a tiny "Mac" if you will, and the memory was essentially like an SSD. Unfortunately my iPhone might have what I'd consider a bad block in it, it hasn't mapped out, it's just ruining a song (iPhone freezes at the exact same point when it hits this song, just like a bad sector on a hard drive) Is there a way I can test this or get the system to map out the block?
This leads me to a question about SSDs that is applicable to this thread. Just like in my iPhone, what's to stop a block in an SSD that's containing data from going bad, and what happens to the file associated with that bad block when this happens? You keep reading about SSDs mapping out bad blocks when they're getting too used up, but how can an SSD controller even spot a block on an SSD that goes bad for reasons the controller may be unaware of?
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Mar 9, 2014 12:17 PM in response to R.K.Orionby PlotinusVeritas,more like a tiny Ipad actually.
Ipad and iPhone devices have the NAND flash soldered directly to their logic boards.
why would you be worried about data loss at all much less on an Iphone.
Everything is about redundancy. Always 2 copies of data OFF-computer or off-phone/ipad
You keep reading about SSDs mapping out bad blocks when they're getting too used up, but how can an SSD controller
Typically SSD arent failing in devices, rather the SSD controllers are.
as recently Sandforce
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Mar 9, 2014 12:34 PM in response to PlotinusVeritasby R.K.Orion,I'm not concerned about the data. With iTunes you almost have to go out of your way to not do a backup. My concern is why did this block of memory, and I'm assuming that's what it is, just fail for no apparent reason?That song where the bad block was had been on that iPhone for years. I see no reason why iOS would be moving things around unnecessarilly, therefore I have to conclude that a block in the memory, SSD, whatever you want to call it, just up and died. Is the bad block mapped out like it would be in an SSD or is it still visible to iOS as a valid writable block when in fact its corrupt.
If bad blocks don't get taken out somehow by the iOS operating system and hardware, and bad blocks keep occurring, I can see this iPhone turning into a useless piece of junk in short order.
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Mar 10, 2014 10:36 AM in response to PlotinusVeritasby R.K.Orion,I received no answer at all on the iPhone section of this site about the memory. It almost seems as if no one knows or no one cares. I would think someone would be developing tools to test an iPhone, just like they have for Macs, but if there are any, I can't find them.
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Mar 10, 2014 11:03 AM in response to R.K.Orionby PlotinusVeritas,R.K.Orion wrote:
I received no answer at all on the iPhone section of this site about the memory. It almost seems as if no one knows or no one cares.
bad blocks keep occurring
They dont...
Your questions above are far too obtuse, and the only ones concerned with such extremely esoteric questions are hardware engineers.
Your questions are like asking about the chemical makeup of LCD substrates, no offense.
Keep it practical and realistic.
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Mar 10, 2014 1:46 PM in response to R.K.Orionby MrJavaDeveloper,I thnk I get what you're asking - it's sort of like you're seeing the flash memory as an HD equivalent, and now its developed a bad block just like an HD can get a bad sector. I did a quick google on it and a string you might want to try is this:
Flash memory bad block iphone
Here's a link to one that describes the controllers lightly:
Whether the controller actually maps out bad blocks, I don't know, but I would think so. A link to the book iPhone and iOS Forensics mentions bad block management on a iPhone. I got that from the link below:
Thats a long link it's one of those online book deals where you can get a peak at what's in the book. The stuff about the controller and bad block management is on pp 68-70. The trouble is it's one of those deals where it may open you up at a different location before hitting you up for a purchase. I'd copy and paste what's there in here but that's probably a copyright violation and the thing won't let anyone copy from it.
From what little I've read, it seems that a block going bad like you described isn't all that uncommon with that type of storage.
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Mar 12, 2014 10:58 AM in response to MrJavaDeveloperby R.K.Orion,Looking at the link from the book, it's fairly evident the flash memory's behavior is like that of an SSD. It really sounds almost like you could essentially claim it is an SSD. I'm just going to assume that if I delete the bad song off the iPhone and put a new version in, the flash memory management system will take care of it.
So here's the next question. Considering the similarity between an SSD and the flash memory in an iPhone, is it just "normal" for a block to drop out in the middle of data in flash memory for no apparent reason? I really don't use the thing that much.It's not like I'm running dozens of apps all the time and taxing the system. It's probably about as close to a static device as you can get. When I first got the thing years ago was when that song went on, and its just been sitting there. If I'd been hammering this thing with use, maybe I'd excuse it but it seems pretty short lived to me.
I don't recall a problem like this ever with an HD. Usually for an HD to start getting bad sectors it seems to me it has to have at least one of the following:
- Be really old and wearing out
- Subjected to impact
- Making noise
There were signs and causes.
I don't think I think to much of data just dropping off the face of the Earth for no good reason. It makes me wonder how good memory technology really is.
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Mar 13, 2014 11:56 AM in response to R.K.Orionby MrJavaDeveloper,You guys can make all the noise you want to about SSDs being "so bad" but if I'm not mistaken Apple expects in the near future to be putting a grand total of zero hard drives in their units. Losing bad blocks on an SSD is a normal thing and the exact same thing could have happened with an HD that had a baby crash.
Personally, I'm interested in seeing how long the things last in the real world. Of course, according to the manufacturers, they last a ka-billion years and get up early in the morning to make coffee and toast while your waking. Reality is something different. I've already seen some posts on this and other sites where SSD's best friend, write cycle depletion, is rearing it's head only 2 years into it's life. I've seen stuff like that several times.
We'll see. We'll see.
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Mar 14, 2014 11:18 AM in response to MrJavaDeveloperby R.K.Orion,What would you do if I were to tell you that I can take a PPC system running Leopard and an internal 2.5" HD and boot it in less time than it takes to boot a new system running Mavericks with an SSD?
I haven't actually measured that, but I think it would be close.
As an FYI getting rid of the bad block on the iPhone memory was a total PIA. There are no tools to the best of my knowledge to do that. I ended up having to do a complete wipe of the phone, the a complere restore.
If an SSD is anything like it is in an iPhone, all I can say it you'd BETTER have a backup and maintain it hourly at a minimum!!
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Mar 16, 2014 8:21 PM in response to R.K.Orionby MrJavaDeveloper,What would you do if I were to tell you that I can take a PPC system running Leopard and an internal 2.5" HD and boot it in less time than it takes to boot a new system running Mavericks with an SSD?
I haven't actually measured that, but I think it would be close.
That's called "Code Bloat." As CPUs get faster, memory gets cheaper, and now SSDs come along, many developers tend to not develop based on code quality or efficiency, but by getting the product out the door as fast as possible. They end up copying and pasting code rather than putting it in libraries where it's stored once. This problem has been around for years. Remember 10 years ago a "killer" machine had a single core, 512K of memory, and maybe a "whopper" disk at 50G.
Did things really seem like they were that bad, or that bottlenecked back then? Considering that I'm sitting on a system w/Mavericks basically "idling" at 2.3G used memory, am I getting that much more done?
The only place people will notice the speed deltas will be with math or CPU intensive applications. Most other stuff that users access is I/O bound by stuff like the net.
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Mar 16, 2014 9:14 PM in response to MrJavaDeveloperby PlotinusVeritas,MrJavaDeveloper wrote:
You guys can make all the noise you want to about SSDs being "so bad" but if I'm not mistaken Apple expects in the near future to be putting a grand total of zero hard drives in their units. Losing bad blocks on an SSD is a normal thing and the exact same thing could have happened with an HD that had a baby crash.
Personally, I'm interested in seeing how long the things last in the real world.
Since you dont know, Ill tell you about the real world of data. Its;
A: redundancy
B: redundancy
C: redundancy
and E: NONE of it is going on, on SSD modules. NONE
tape
optical
and conventional HD
not SSD
MrJavaDeveloper wrote:
Apple expects in the near future to be putting a grand total of zero hard drives in their units.Speculating about future products isnt allowed on this board.
However, SSD are not storage modules, NOR is any notebook / laptop a "data storage device" (SSD or HD, doesnt matter which)
Theyre for:
A: making data
B: moving data
C: consuming data
and NOT for D: storing data
always has been the case, ever shall be the case.
Any and all people who think, wrongly, that a computer is a data storage device, will, without fail reap a disaster known as data loss.
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Mar 16, 2014 9:33 PM in response to PlotinusVeritasby MrJavaDeveloper,I for one, don't really trust SSDs just yet. Although I know a lot of people aren't having problems with them, others are. My favorite "feature" is their ability to completely wipe themselves of data. I'm not sure which are (or were) doing this and how rare (or common) this little feature is, but it's one I can live without.
As an FYI, I do periodic clones of my data to numerous HDs, and maintain Time Machine's as well. I've been stung by data loss before. Some say I'm paranoid, but I haven't lost a file in over 10 years.
You have a lot more faith in optical storage than I do.
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Mar 16, 2014 10:34 PM in response to MrJavaDeveloperby PlotinusVeritas,MrJavaDeveloper wrote:
As an FYI, I do periodic clones of my data to numerous HDs, and maintain Time Machine's as well. I've been stung by data loss before. Some say I'm paranoid, but I haven't lost a file in over 10 years.
You have a lot more faith in optical storage than I do.
Not talking about CHEAP commercial optical, rather professional archival Optical.
they 2 are totally diff. creatures.
You said:
I do periodic clones of my data to numerous HDs,
Very smart, very wise, ... unfortunately its very rare for people to do that.
If you're doing that, then you're "awesome"
Ive got over 100 hard drives, and have data parked on 2 diff. continents on servers.
as for archival DVD / optical, few people know anything about high quality optical storage:
True longevity, long-term professional data protection. The Gold and Platinum standard
When it comes to long-term data protection, there is optical and there is NOTHING else, period. While modern notebooks and macbooks have forgone, for the most part internal optical DVD/CD readers/writers, this is most entirely due to the fact that commercial videos and movies have gone to online rentals and Itunes purchases, additionally nearly all software now is online purchase and download. The other reason for this is the removal of a 'high' failure point of an internal optical drive which is both mechanically complex, prone to dust on the laser diode lens due to users inserting dusty disks / media, and that the superdrive is not currently capable of fitting in the super-slim form factor machines such as the current Imac, Macbook Pro and especially the Macbook Air. However external USB DVD burners and readers are going nowhere anytime in the foreseeable future,... and until a new optical technology emerges for data preservation, DVD writers aren’t going anywhere.
Online media and software however has no bearing or impact on the fact that the fragile nature of ferromagnetic storage has not gotten any better now than it was 20 years ago aside from improved production specifications in physical hard drive builds. There are many that would point out in incorrect conjecture that “optical is a dying or dead medium”, such people don’t know what they're talking about and are directing their comments at optical based movies and software, not data archiving and protection which in fact is growing in scope, not declining.
While low grade consumer DVD blank media has a life between 8-15 years best case, professional DVD blank media has both a different standard of manufacture and chemically a different read/write layer that has serious professional longevity with 19 years real world testing and age-stress progression testing proving that at the very minimum, 60 years viable protection if stored correctly and in some patented mfg. standards, 100+ years data retention and preservation. While "gold" disks have been superceeded by even better technology manufacted disks, this is still a term of reference as implying professional DVD blank media.
In fact a new breed of disks that use a higher powered write-laser are commercially available and have a rated life of 1000 years and are referred to as M-DISK. Governments, military, and professional businesses have much time and money invested in high-importance data storage on optical media out of necessity given the extremely fragile nature of ferromagnetic storage. Such new optical technology creates permanent pits in the disk surface, which are not affected by light like consumer DVD media which uses a organic dye layer to write and read from of the data.
While DVD media are only 4.7GB single layer in scope, and cannot store massive amounts of data, not even by the 100-pack, most vitally important priority data people own are picture collections, texts, audio, and other small scale media. In such an evaluation, high priority data is necessitated out of prudence, to be written to professional archival grade DVD media, not low-grade consumer DVD blanks. Such professional DVD blank media is only roughly 30% more expensive than low grade consumer DVD blank media.
Archive Diversity, Century-disk blank DVDs
As important as having multiple copies of your data hub (vital files) is having those copies somewhere that long-term data retention is a guarantee. As stated earlier, given the second law of thermodynamics, any and all current mfg. HD will, under perfect storage conditions tend themselves to depolarization and a point will be reached, even if the HD mechanism is perfect, that the ferromagnetic read/write surface of the platter inside the HD will entropy to the point of no return for data extraction.
HD life varies, but barring mechanical failure, 3-8 years typically. Hard drive mortality spikes in the first month or so, and then falls to nill before, after time, rising gradually and assuredly. This initial ‘infant mortality’ needs to be check especially in instances of new static HD archives.
Archival DVD blank media only costs an average of 20% more than conventional low grade DVD media but has an extremely low reject rate and most importantly an extremely high life rating, many 60+ years, and century disks which are rated for 100, or 150+ years if stored under cool dark ideal conditions. There is little more frustrating than the thought much less the reality of losing years or a lifetimes worth of work over a $20 price difference between a 100-pack of low grade storage DVD media and professional DVD blank media.
It is ironic that many of us will buy expensive computers and spend years and great effort creating data but don’t think twice about buying unreliable storage media to safeguard our valuable work, pictures, documents, books, and things so important to us and others.
In the case of ‘large data’ where many 100’s of DVD blanks becomes unrealistic for your data hub preservation, having revolving HD archives copied and checked on a regular basis becomes vitally important but more importantly as supplemented by offsite storage hosting of your data in at least 2 locations where HD natural degradation is of no concern since there is no single HD at a hosting farm, typically, where data can crash and be lost.
In considering the idealized use of DVD archival media, archived hard drives, and offsite-hosting storage, each has its benefits and drawbacks. In the case of DVD media, one cannot typically archive large amounts of data in the 2+ terabyte range realistically since this would involve a very large number of disks amounting to 212 DVD blanks per terabyte archived. In the bottleneck limitation of DVD media, if one has large data, reserve at the very least priority “cannot lose at any cost data” for burning to this option for safekeeping.
Advantages of HD archives are obvious in that 2.5” are very compact, much more reliable than years past, and massive amounts of data can be stored securely with ease in a very small space. Roughly 60 terabytes of data can be stored in a volume the size of a shoebox. The drawback of this type of storage is natural long-term degradation of the ferromagnetic data stored on the disks, and a potential EM pulse can wipe out an entire data archive in a matter of milliseconds. Additionally these HD need to be protected from theft, and exposure by means of either a firebox, safe, or safety deposit box, or a likewise secure and environmentally isolated container. To safeguard against degradation, optimally you would upgrade these HD archives every year or two just as you would the batteries in your smoke detector, even if still good.
Advantages of hosting archives are that, as stated, there is no single location (in terms of large data farms) for HD degradation to bring down your archived data hub. The best advantage of online private and secure data archiving is that your data is protected from fires, and natural disasters at your location, and this data can be pulled from anywhere on earth with ease. The drawbacks of this type of storage archive is if you fail to pay and forget to update payment for your hosting storage, your data can be erased, additionally if you don’t take steps to safeguard this data by hiding it, encrypting it, or likewise measures, it can be attacked, erased, or corrupted by third parties. This offsite online archive option is best idealized as a third location to park a copy of your files to be archived.
Use DVD+R for your archives, not DVD-R
Since your data is so valuable, its is a stated necessity that you not purchase low grade retail DVD blank media rather ‘century-disks’ as meant 60+ year or 100+ year professional archival DVD blank media (such as Taiyo Yuden or otherwise). These blank media average only 20% more than consumer level DVD blanks, but are extremely reliable, have an extremely low reject rate of bad blanks, and your valuable data and work is most certainly worth the cost of 100-pack of DVD blanks which are only $15 or so more than the typical blanks.
As to the type of professional DVD blank media: DVD-R is inferior for data preservation for several reasons: error correction, wobble tracking, and writing method. For a DVD to track where it is on the disc, it uses three things: the ‘wobble’ of the data track to tell where it is in the track, the position of the track to tell where it is on the disc, and some additional information where on the disc to tell where the track begins and ends. On –R media, the ATIP is stored as a frequency modulation in the wobble itself; since the wobble changes subtly to encode data, it is impossible to use with the small size of tracks DVD requires, as electric noise in the laser pickup and wobbles introduced by the electric motor spinning the disc, these could easily be read as frequency changes in the real track itself.
On DVD-R this problem had been attempted to be solved by ‘pre-pits’ where spikes in the amplitude of the wobble appear due to pits fully out of phase with the rest of the track (between two spirals of the track, where there is no data). This can be viewed as a simple improvement over CD-R as it makes it easier to track the wobble. This method has one flaw: due to electric noise in the laser pickup, it would be very easy to miss the pre-pit (or read one that wasn’t actually there) if the disc were damaged or spun at fast speeds. DVD-R traded hard to track frequency changes for hard to read wobble-encoded data.
On a DVD+R there is a better write method. Instead of changing the frequency of the wobble, or causing amplitude spikes in the wobble, they use complete phase changes. Where DVD-R’s methods make you choose between either easy wobble tracking or easy ATIP reading, DVD+R method makes it very easy to track the wobble, and also very easy to encode data into the wobble. DVD+R method is called ADIP (Address In Pre-groove).
Now, the third item on the list: how DVD+R discs burn better. ATIP/pre-pit/ADIP stores information about optimum power control settings. DVD-R basically fails on all three accounts because DVD+R simply includes far more information about the media in the ADIP data than DVD-R does in it’s pre-pit data. DVD+R includes four optimum profiles, one for four major burning speeds. Each of these profiles includes optimum power output based on laser wavelength, more precise laser power settings, and other additional information. With this information, any DVD+R burner can far more optimize its burning strategy to fit the media than it can with DVD-R, thereby providing better burns.
DVD+R also gives four times more scratch space for the drive to calibrate the laser on; more space can only improve the calibration quality. So DVD+R media exists to simply produce better burns and protect your data better, which when it comes to data hub archiving is of vital importance.



