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Can you put them in a battery powered box, with no data connection? I'm thinking my little consumer grade APC could power one for many days (months?). I'll have

by edoceo 5y ago

Can you put them in a battery powered box, with no data connection? I'm thinking my little consumer grade APC could power one for many days (months?). I'll have to check the numbers

wtallis 5y ago
You don't need to keep SSDs powered continuously. You just need to power them on periodically and read all the data on the drive so the SSD controller has the chance to notice data degradation and repair it before it becomes unrecoverable. This does not need to be done more often than once per year. For SSDs that are exclusively used for archival and thus never approach the end of their rated write endurance, it may be adequate to do this once per decade. Basically, any backup strategy that includes a sensible amount of testing and verification should suffice.
- JaimeThompson 5y ago
  IBM, Samsung, Intel, and other manufactures of flash and flash based products disagree with you on that only once per year time frame. As flash gets more and more dense leakage from the cells becomes a much more difficult problem to solve.
  - wtallis 5y ago
    Last time I checked, those companies were still adhering to the JEDEC standards for how they define SSD write endurance, which is based on how worn-out the flash can be while still meeting certain unpowered data retention thresholds. For consumer SSDs, that threshold is one year unpowered and stored at 30°C. [1] All of the challenges of unpowered data retention are already being addressed in the normal course of bringing new generations of flash and SSDs to market, even though nobody is yet making drives specifically tailored for that use case. Additionally, lightly-used flash has error rates that are orders of magnitude smaller than flash that has reached or is approaching its write endurance limit. Which is why an archive-only SSD can very reasonably be expected to provide unpowered data retention far in excess of one year. [1] For enterprise drives, the specified duration is shorter but the storage temperature is higher. The warrantied write endurance is also typically higher, so those drives are willing to take their flash to a more thoroughly worn-out state.
selfhoster11 5y ago
At this point, you might as well just invest in a tape library

by edoceo 5y ago

Can you put them in a battery powered box, with no data connection? I'm thinking my little consumer grade APC could power one for many days (months?). I'll have to check the numbers

wtallis 5y ago

You don't need to keep SSDs powered continuously. You just need to power them on periodically and read all the data on the drive so the SSD controller has the chance to notice data degradation and repair it before it becomes unrecoverable. This does not need to be done more often than once per year. For SSDs that are exclusively used for archival and thus never approach the end of their rated write endurance, it may be adequate to do this once per decade. Basically, any backup strategy that includes a sensible amount of testing and verification should suffice.

JaimeThompson 5y ago
IBM, Samsung, Intel, and other manufactures of flash and flash based products disagree with you on that only once per year time frame. As flash gets more and more dense leakage from the cells becomes a much more difficult problem to solve.
- wtallis 5y ago
  Last time I checked, those companies were still adhering to the JEDEC standards for how they define SSD write endurance, which is based on how worn-out the flash can be while still meeting certain unpowered data retention thresholds. For consumer SSDs, that threshold is one year unpowered and stored at 30°C. [1] All of the challenges of unpowered data retention are already being addressed in the normal course of bringing new generations of flash and SSDs to market, even though nobody is yet making drives specifically tailored for that use case. Additionally, lightly-used flash has error rates that are orders of magnitude smaller than flash that has reached or is approaching its write endurance limit. Which is why an archive-only SSD can very reasonably be expected to provide unpowered data retention far in excess of one year. [1] For enterprise drives, the specified duration is shorter but the storage temperature is higher. The warrantied write endurance is also typically higher, so those drives are willing to take their flash to a more thoroughly worn-out state.

selfhoster11 5y ago

At this point, you might as well just invest in a tape library