4 ms·

I have old pictures I took, they were on a SD card. For some reason a few of those files are 0 bytes, meaning they probably went corrupt at some point. It seem

by jokoon 5y ago

I have old pictures I took, they were on a SD card. For some reason a few of those files are 0 bytes, meaning they probably went corrupt at some point. It seems that it also happens on my SSD. For some other reason, windows explorer seems to crash or hang when I browse folder with a lot of images. SSD are known to have a short life expectancy. I wonder if there is a market for very long life expectancy for HDDs. I mean any type of data storage that can last for 10 years without failure would have value. Of course magnetic tape systems exist but I would guess that very durable HDD would still be better.

calvinmorrison 5y ago
CDs are probably the sweet spot
- timw4mail 5y ago
  For cheaply storing data, sure. The dye on burnable discs tends to degrade over time, though, making them poor for archival purposes.
  - dragontamer 5y ago
    Everything degrades over time. An archival quality DVD has dyes that resists the bitrot. Archival quality magnetic mediums (HDDs or Tape, or floppies) also resist the bitrot... but they're not immune. The only way to fully avoid bitrot is to constantly read-and-rewrite the data. You need to read the data before it degrades: that could be once a year, or maybe every few months. But cold-storage is just a devilishly hard problem. Its probably best to just not deal with that at all. Just get a NAS and read/rewrite the data automatically (aka: "scrub" your data in ZFS terms)
- dragontamer 5y ago
  they WERE the sweet spot at one point (at least, DVDs were), but they've fallen behind and are no longer worth it. All the issues with hard drives (single "read" mechanism, limiting bandwidth) are doubly so when the medium exists outside of the read-mechanism and multiple manufacturers need to try to stay compatible with each other. It seems difficult to improve the medium independently of the read-mechanism. I don't really know how the tape-drive industry manages to keep up. Tape just has some huge fundamental advantages in surface area I guess... but Tape also only promises read compatibility for 2-generations. So the whole industry manages to move forward on a decent cadence. --------- SSDs are now the right size and price for typical end-user devices. But HDDs are still the king of capacity for all datasets below 50TBs, while Tape reigns supreme at the highest end in price per TB.
  - xtiansimon 5y ago
    > “ they WERE the sweet spot at one point (at least, DVDs were), but they've fallen behind and are no longer worth it.” Are you inclined M-Disk in that group?
    - dragontamer 5y ago
      By memory, it feels like M-Disk was a bit "too late" to the party. By that point, BluRays came out and it was cheaper/more reasonable to just double-write your data on two BluRays. Eventually, M-Disk BluRays came out, but no one used optical anymore. M-Disks were probably the best archival format for optical when they came out (at least, if their archive-quality claims are truly as good as they claim). But they always were a bit more expensive and/or late to the party. Being #1 in optical when optical is dying is not really a win...
      - xtiansimon 5y ago
        I get your point. Certainly not if you want to buy blank media, or replace a burner. Like minidisc. That was a fantastic medium. I loved those discs as artifacts—like having your old mix tapes. But once the player broke...only some random players on EBay.
- LorenPechtel 5y ago
  They used to be. These days spinning rust is cheaper than optical.
willis936 5y ago
HDDs have awful MTTF compared to SSDs. Where HDDs shine is when you fill them up, unplug them, and put them in a box for decades. SSDs are much more reliable than HDDs if you want to access the data, they just need to be powered and never written to.
- wtallis 5y ago
  SSD data retention is also excellent if you only ever fill it up once. Data retention only becomes a problem if you use up most of the write endurance. Whether the SSD is powered or not during the long periods where you're not accessing the data has minimal effect. They're still a horrible data archival solution, but mainly because of the high price per TB.
  - dragontamer 5y ago
    > Whether the SSD is powered or not during the long periods where you're not accessing the data has minimal effect. I've heard conflicting reports on this. Ultimately, any storage technology is about storing data. This can be done magnetically (aka: bits are tiny little magnets pointing in certain directions), as long as the magnets don't change, you can read back the data fine. Or it can be done optically (ex: the dye inside of CD-roms, DVD or BluRay). As long as the dye remains a certain color, you can read it back fine. Magnets lose charge over time, dyes can change color (especially if they're exposed to the sun). You won't notice over a year or even 2 years, but after 5, 10, or 15 years, things change enough that you start getting errors. SSDs store data by punching an electrical charge into a transistor. The barrier is such that the electrical charge doesn't want to leak out: but... what is the rate of that leakage? All materials "leak" charge over time. And if the voltage changes dramatically, the change-in-voltage will change the data (and thus you'll lose data over time). -------------------------------- Some SSDs, such as the Samsung 830, were well known for leaking charge and causing issues. Today, we use stacked 3D NAND, which is a different transistor type than the planar NAND on the Samsung 830, but that doesn't fundamentally answer the question of "What is the leakage current" and "how long do we have before enough voltage leaves the transistor to corrupt the data?"

by jokoon 5y ago

calvinmorrison 5y ago

CDs are probably the sweet spot

timw4mail 5y ago
For cheaply storing data, sure. The dye on burnable discs tends to degrade over time, though, making them poor for archival purposes.
- dragontamer 5y ago
  Everything degrades over time. An archival quality DVD has dyes that resists the bitrot. Archival quality magnetic mediums (HDDs or Tape, or floppies) also resist the bitrot... but they're not immune. The only way to fully avoid bitrot is to constantly read-and-rewrite the data. You need to read the data before it degrades: that could be once a year, or maybe every few months. But cold-storage is just a devilishly hard problem. Its probably best to just not deal with that at all. Just get a NAS and read/rewrite the data automatically (aka: "scrub" your data in ZFS terms)
dragontamer 5y ago
they WERE the sweet spot at one point (at least, DVDs were), but they've fallen behind and are no longer worth it. All the issues with hard drives (single "read" mechanism, limiting bandwidth) are doubly so when the medium exists outside of the read-mechanism and multiple manufacturers need to try to stay compatible with each other. It seems difficult to improve the medium independently of the read-mechanism. I don't really know how the tape-drive industry manages to keep up. Tape just has some huge fundamental advantages in surface area I guess... but Tape also only promises read compatibility for 2-generations. So the whole industry manages to move forward on a decent cadence. --------- SSDs are now the right size and price for typical end-user devices. But HDDs are still the king of capacity for all datasets below 50TBs, while Tape reigns supreme at the highest end in price per TB.
- xtiansimon 5y ago
  > “ they WERE the sweet spot at one point (at least, DVDs were), but they've fallen behind and are no longer worth it.” Are you inclined M-Disk in that group?
  - dragontamer 5y ago
    By memory, it feels like M-Disk was a bit "too late" to the party. By that point, BluRays came out and it was cheaper/more reasonable to just double-write your data on two BluRays. Eventually, M-Disk BluRays came out, but no one used optical anymore. M-Disks were probably the best archival format for optical when they came out (at least, if their archive-quality claims are truly as good as they claim). But they always were a bit more expensive and/or late to the party. Being #1 in optical when optical is dying is not really a win...
    - xtiansimon 5y ago
      I get your point. Certainly not if you want to buy blank media, or replace a burner. Like minidisc. That was a fantastic medium. I loved those discs as artifacts—like having your old mix tapes. But once the player broke...only some random players on EBay.
LorenPechtel 5y ago
They used to be. These days spinning rust is cheaper than optical.

willis936 5y ago

HDDs have awful MTTF compared to SSDs. Where HDDs shine is when you fill them up, unplug them, and put them in a box for decades. SSDs are much more reliable than HDDs if you want to access the data, they just need to be powered and never written to.

wtallis 5y ago
SSD data retention is also excellent if you only ever fill it up once. Data retention only becomes a problem if you use up most of the write endurance. Whether the SSD is powered or not during the long periods where you're not accessing the data has minimal effect. They're still a horrible data archival solution, but mainly because of the high price per TB.
- dragontamer 5y ago
  > Whether the SSD is powered or not during the long periods where you're not accessing the data has minimal effect. I've heard conflicting reports on this. Ultimately, any storage technology is about storing data. This can be done magnetically (aka: bits are tiny little magnets pointing in certain directions), as long as the magnets don't change, you can read back the data fine. Or it can be done optically (ex: the dye inside of CD-roms, DVD or BluRay). As long as the dye remains a certain color, you can read it back fine. Magnets lose charge over time, dyes can change color (especially if they're exposed to the sun). You won't notice over a year or even 2 years, but after 5, 10, or 15 years, things change enough that you start getting errors. SSDs store data by punching an electrical charge into a transistor. The barrier is such that the electrical charge doesn't want to leak out: but... what is the rate of that leakage? All materials "leak" charge over time. And if the voltage changes dramatically, the change-in-voltage will change the data (and thus you'll lose data over time). -------------------------------- Some SSDs, such as the Samsung 830, were well known for leaking charge and causing issues. Today, we use stacked 3D NAND, which is a different transistor type than the planar NAND on the Samsung 830, but that doesn't fundamentally answer the question of "What is the leakage current" and "how long do we have before enough voltage leaves the transistor to corrupt the data?"