Personal computing discussed
Moderators: renee, mac_h8r1, Nemesis
meerkt wrote:I never got the idea of multi-pass erasing. If old data can be read after being overwritten, why don't HDD manufacturers use that to double or triple the capacity?
Waco wrote:I don't even get the option of a DoD or NSA approved erase...I get to degauss, crush, and shred up our old drives at work. I wish I could say I get to do that myself occasionally but they won't let me play with the shredder.
meerkt wrote:I never got the idea of multi-pass erasing. If old data can be read after being overwritten, why don't HDD manufacturers use that to double or triple the capacity?
Waco wrote:I don't even get the option of a DoD or NSA approved erase...I get to degauss, crush, and shred up our old drives at work. I wish I could say I get to do that myself occasionally but they won't let me play with the shredder.
just brew it! wrote:Waco wrote:The extreme erasure methods are so that you don't need to physically destroy the drive (and can potentially re-use it).I don't even get the option of a DoD or NSA approved erase...I get to degauss, crush, and shred up our old drives at work. I wish I could say I get to do that myself occasionally but they won't let me play with the shredder.
Captain Ned wrote:Based on Waco's stated location, I understand why reuse isn't an option. Even my 2-bit State regulatory operation drills every spinning drive upon decom. Since we're too cheap to buy SSDs for laptops, I doubt they've even thought of proper (and easy) destruction methods for same.
just brew it! wrote:Not really the same thing, but SMR drives actually *do* partially erase previous valid data with new data: https://en.wikipedia.org/wiki/Shingled_ ... _recording
just brew it! wrote:The extreme erasure methods are so that you don't need to physically destroy the drive (and can potentially re-use it).
Captain Ned wrote:Based on Waco's stated location, I understand why reuse isn't an option. Even my 2-bit State regulatory operation drills every spinning drive upon decom. Since we're too cheap to buy SSDs for laptops, I doubt they've even thought of proper (and easy) destruction methods for same.
Waco wrote:I'd be pretty happy to just crush the drives...glass platters simply don't leave much when they shatter.
Waco wrote:I don't even get the option of a DoD or NSA approved erase...I get to degauss, crush, and shred up our old drives at work. I wish I could say I get to do that myself occasionally but they won't let me play with the shredder. :(
Waco wrote:Not really the same thing, but SMR drives actually *do* partially erase previous valid data with new data: https://en.wikipedia.org/wiki/Shingled_ ... _recording
Yep. They're a total PIA to deal with, but if you design your storage stack carefully they are a godsend in terms of cost/bit stored. If your workload is bad for them, though, god help you. Enjoy your handful of IOPs per drive...
Captain Ned wrote:A sad data destruction story: A co-worker of mine passed away roughly around 16 years ago (lung cancer). His widow contacted the Department to ask us when we would be over to remove all of his accumulated "office" stuff from the house. When the hoard was returned to my office we discovered roughly 1,500 3.5" floppies covering some 15 years of work. As this was before the advent of media shredding devices/vendors, the entire office staff spent a couple of weeks (in our "spare" time) ripping off the sliding shield, popping open the case, pulling the disc, and popping out the metal drive hub so that we could put just the magnetic media in our paper-based shred bins (we'd called the shredding vendor and that's all they wanted in the bins). We all spent the next 2 weeks nursing all sorts of cuts/abrasions to fingers caused mainly by prying off the sliding shield.
Ryu Connor wrote:I'd note that as of like 2007 DoD 5220 no longer accepts multi-pass erasure (DBAN for example) as a valid method of data destruction.
Waco wrote:meerkt wrote:I never got the idea of multi-pass erasing. If old data can be read after being overwritten, why don't HDD manufacturers use that to double or triple the capacity?
Because recovering that data is *incredibly* slow and expensive.
just brew it! wrote:Sure. But you can't read it back.Not really the same thing, but SMR drives actually *do* partially erase previous valid data with new data
meerkt wrote:Waco wrote:meerkt wrote:I never got the idea of multi-pass erasing. If old data can be read after being overwritten, why don't HDD manufacturers use that to double or triple the capacity?
Because recovering that data is *incredibly* slow and expensive.
So how about that:
Let's assume data overwritten once reads at .1 speed, and overwritten twice at .01. Seems fine for nearline and offline backup?
just brew it! wrote:Not really the same thing, but SMR drives actually *do* partially erase previous valid data with new data
Sure. But you can't read it back.
notfred wrote:Modern drives tend to have firmware and parameters on a track that's only readable by the drive and not by the host. If you use a bulk eraser on them then you have likely erased that and the drive is useless.
Captain Ned wrote:Three or four passes with a carbide-tip 1/4 drill through the entire drive casing in the platter area will so shatter the platters as to make shredding mere excess
just brew it! wrote:notfred wrote:Modern drives tend to have firmware and parameters on a track that's only readable by the drive and not by the host. If you use a bulk eraser on them then you have likely erased that and the drive is useless.
Given the high coercivity of modern media, you need a fairly powerful magnet to degauss recent drives. I'm pretty sure my antique bulk tape eraser would have no effect (maybe I'll try it sometime on a drive I'm planning on junking, just for grins).
Onlyzen wrote:hi southrncomfortjm,
Are you still interested to sell your Pc? One of my friends is interested to buy