BitDepth 495 - October 18
11/01/09 17:44 Filed in: BitDepth - October 2005
Pay attention to the warning signs of faiing media.
Data from a dying disk
The symphony of the feather thin write heads (bottom) and the disk platters can sometimes come to a disconcerting halt. Photo by Mark Lyndersay.
It’s one thing to write about backups and quite another to depend on them.
After four years of working with digital images exclusively, I had quite a scare when my workflow failed far from home base in a hotel room.
After working all morning filling a compact flash card, my laptop froze while transferring the files to the computer for post-processing.
After a reboot, the system became unresponsive again during the file download, so I copied everything before the file that seemed to be aborting the transfer and then copied all the files right after it.
That image was a dead loss, but only after reformatting the card in camera several times did it become clear that the card had developed a serious flaw.
The media, after being written to repeatedly, had begun to fail.
Every time you save or copy a file to disk, tiny mechanical heads on a hard disk flit back and forth seeking space mapped as empty by your computer. When the computer encounters a patch of disk space that’s not reading or writing correctly, it marks the defective sector of the disk as unusable and moves on.
But when a critical mass of these problems pile up, you’ll begin to experience subtle warnings of pending trouble as you use your computer system.
The compact flash card I’d been using had reached that point, and the sector lockouts that protect data during a normal format were no longer enough to stop bad writes.
Misery loves company, so it followed with sitcom synchronicity that a friend would drop by with a laptop that was no longer booting.
I got the system to start up briefly and failed to do the one important thing you must do when dealing with faltering media and that’s to copy everything irreplaceable off the problem disk.
What followed was long hours of working on a deathbed disk by appealing to all the digital deities to keep it running long enough to copy crucial files off it. Once everything had been transferred, I tried to reformat it and it refused to mount ever again after that.
The moral of the story? All media will fail, so have a plan for dealing with it when the time comes. I got lucky with the compact flash card and didn’t have to resort to specialised software to recover files trapped on it.
There is software, however, that’s designed specifically to scavenge a problematic media card for the image files trapped on it and to restore computer hard disks to a usable state but that’s generally a job for professionals.
All the digital voodoo in the world is no replacement for a good system of backing up that safeguards your information.
Today’s hard drives and flash media pack ever more technology into smaller packages.
Once hard drives were the size of a paperback with big solid platters and hefty read-write arms that wrote your data with loose tolerances to the polished surface of the disks.
Now hard drives pack multiple super-thin platters into a box barely bigger than a matchbox. Flash media capacities double and triple every year but the physical dimensions can’t get bigger. Something, as they say, has to give and that’s turned out to be drive reliability. If you keep getting more for less, the dividends end up being extracted elsewhere and it’s turning out to be our little personal losses.
Warning signs.
If files won’t open or open showing gibberish or seem to take unusually long to save, there’s a good chance that your disk may be heading off to the great spindle in the sky. Listen out for audible clicking from the drive and feel for unusual heat coming from the surface of the drive casing.
Every modern hard disk comes equipped with Self Monitoring Analysis and Reporting Technology or SMART reporting; a technology pioneered by Compaq.
Many modern PCs are equipped to check the drive parameters using this technology but you can find free software that offers immediate feedback when you’re in worrisome situations with a potentially flaky drive.
Be warned, though that I’ve seen two recent drives cheerily report to a SMART utility that they were just fine, thank you, even as they went into a smoking World War II fighter-plane tailspin.
Salvage tips
If you need to salvage data from a failing hard drive, do it the minute you realise the drive is hosed. You may not get a second chance.
That means having somewhere to put your files handy. For most people, that means a fair sized flash drive; or better yet, an external drive. It’s risky trying to burn data from a failing hard drive because writing to the disk in any way only increases the possibility of damaging the information that’s already on it.
The symphony of the feather thin write heads (bottom) and the disk platters can sometimes come to a disconcerting halt. Photo by Mark Lyndersay.
It’s one thing to write about backups and quite another to depend on them.
After four years of working with digital images exclusively, I had quite a scare when my workflow failed far from home base in a hotel room.
After working all morning filling a compact flash card, my laptop froze while transferring the files to the computer for post-processing.
After a reboot, the system became unresponsive again during the file download, so I copied everything before the file that seemed to be aborting the transfer and then copied all the files right after it.
That image was a dead loss, but only after reformatting the card in camera several times did it become clear that the card had developed a serious flaw.
The media, after being written to repeatedly, had begun to fail.
Every time you save or copy a file to disk, tiny mechanical heads on a hard disk flit back and forth seeking space mapped as empty by your computer. When the computer encounters a patch of disk space that’s not reading or writing correctly, it marks the defective sector of the disk as unusable and moves on.
But when a critical mass of these problems pile up, you’ll begin to experience subtle warnings of pending trouble as you use your computer system.
The compact flash card I’d been using had reached that point, and the sector lockouts that protect data during a normal format were no longer enough to stop bad writes.
Misery loves company, so it followed with sitcom synchronicity that a friend would drop by with a laptop that was no longer booting.
I got the system to start up briefly and failed to do the one important thing you must do when dealing with faltering media and that’s to copy everything irreplaceable off the problem disk.
What followed was long hours of working on a deathbed disk by appealing to all the digital deities to keep it running long enough to copy crucial files off it. Once everything had been transferred, I tried to reformat it and it refused to mount ever again after that.
The moral of the story? All media will fail, so have a plan for dealing with it when the time comes. I got lucky with the compact flash card and didn’t have to resort to specialised software to recover files trapped on it.
There is software, however, that’s designed specifically to scavenge a problematic media card for the image files trapped on it and to restore computer hard disks to a usable state but that’s generally a job for professionals.
All the digital voodoo in the world is no replacement for a good system of backing up that safeguards your information.
Today’s hard drives and flash media pack ever more technology into smaller packages.
Once hard drives were the size of a paperback with big solid platters and hefty read-write arms that wrote your data with loose tolerances to the polished surface of the disks.
Now hard drives pack multiple super-thin platters into a box barely bigger than a matchbox. Flash media capacities double and triple every year but the physical dimensions can’t get bigger. Something, as they say, has to give and that’s turned out to be drive reliability. If you keep getting more for less, the dividends end up being extracted elsewhere and it’s turning out to be our little personal losses.
Warning signs.
If files won’t open or open showing gibberish or seem to take unusually long to save, there’s a good chance that your disk may be heading off to the great spindle in the sky. Listen out for audible clicking from the drive and feel for unusual heat coming from the surface of the drive casing.
Every modern hard disk comes equipped with Self Monitoring Analysis and Reporting Technology or SMART reporting; a technology pioneered by Compaq.
Many modern PCs are equipped to check the drive parameters using this technology but you can find free software that offers immediate feedback when you’re in worrisome situations with a potentially flaky drive.
Be warned, though that I’ve seen two recent drives cheerily report to a SMART utility that they were just fine, thank you, even as they went into a smoking World War II fighter-plane tailspin.
Salvage tips
If you need to salvage data from a failing hard drive, do it the minute you realise the drive is hosed. You may not get a second chance.
That means having somewhere to put your files handy. For most people, that means a fair sized flash drive; or better yet, an external drive. It’s risky trying to burn data from a failing hard drive because writing to the disk in any way only increases the possibility of damaging the information that’s already on it.
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