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The purpose of these drives is not for archive. In fact, individual SSDs in general should not be used for archiving. They are for performance. Since we're p

by AdamN 4y ago

The purpose of these drives is not for archive. In fact, individual SSDs in general should not be used for archiving. They are for performance. Since we're probably talking about laptops or phones typically, there's also the loss of the device or catastrophic failure (fire?) to worry about so there needs to be a disaster recovery plan regardless.

5e92cb50239222b 4y ago
No need for any "archiving". I live in a country where you get drafted for a mandatory army service once you reach 18 years of age. The user leaves his desktop (or laptop) at home, goes to the army, returns back in a year, and — whoops — there's no data left on the drive. You know the user should have kept backups, and I know that, but your average Joe is going to be pretty unpleasantly surprised.
- londons_explore 4y ago
  Thats why the drive should have a battery backup builtin lasting many years... Years of battery life isn't tricky, because the drive can, upon being unpowered for a week, rewrite data to be more durable at the expense of access time. 'recovery blocks' can be created which allow the recovery of any unreadable block on the drive. The drive can then wake up and rewrite data only as often as needed based on temperature and the error rate found on the last rewrite. For example, on a 1TB SSD, you might only rewrite 5GB/day, taking just 10 seconds at 1 watt. On a 5 Wh battery, thats 5 years. And thats a worst case - keep it somewhere cool, and the rewrite rate might be halved, doubling battery life. Have the drive half full, and the battery life is doubled again (due to half as much to rewrite), and multiplied by 8 (due to the ability to use the spare space for ECC data). So a half full drive stored in a cool place might be able to last 160 years. Obviously at that point, the battery self discharge and power to run timers will dominate.

by AdamN 4y ago

5e92cb50239222b 4y ago

No need for any "archiving". I live in a country where you get drafted for a mandatory army service once you reach 18 years of age. The user leaves his desktop (or laptop) at home, goes to the army, returns back in a year, and — whoops — there's no data left on the drive. You know the user should have kept backups, and I know that, but your average Joe is going to be pretty unpleasantly surprised.

londons_explore 4y ago
Thats why the drive should have a battery backup builtin lasting many years... Years of battery life isn't tricky, because the drive can, upon being unpowered for a week, rewrite data to be more durable at the expense of access time. 'recovery blocks' can be created which allow the recovery of any unreadable block on the drive. The drive can then wake up and rewrite data only as often as needed based on temperature and the error rate found on the last rewrite. For example, on a 1TB SSD, you might only rewrite 5GB/day, taking just 10 seconds at 1 watt. On a 5 Wh battery, thats 5 years. And thats a worst case - keep it somewhere cool, and the rewrite rate might be halved, doubling battery life. Have the drive half full, and the battery life is doubled again (due to half as much to rewrite), and multiplied by 8 (due to the ability to use the spare space for ECC data). So a half full drive stored in a cool place might be able to last 160 years. Obviously at that point, the battery self discharge and power to run timers will dominate.