3 ms·

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.

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.