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Is there any way to extend the lifetime of a SSD by allowing its capacity to decrease by replenishing its reserve of replacement blocks so that the SSD could co

Is there any way to extend the lifetime of a SSD by allowing its capacity to decrease by replenishing its reserve of replacement blocks so that the SSD could continue to operate until it runs out of writable blocks?

verall 5y ago
Generally, you would look to a datacenter line of SSD which is rated for much higher endurance. These are typically overprovisioned much more than consumer ssds in order to meet the endurance requirements. I think most OEMs opt not to let you choose this sort of thing and rather bury it into the drive firmware.
lathiat 5y ago
Theoretically this would be possible but probably wouldn't help much in practice. Writes on an SSD aren't mapped 1:1 from "logical" address to physical address - they constantly balance and move writes around the entire device (the "Flash Translation Layer" it's sometimes called). As a result once you have exhausted the normal reserve capacity (perhaps allowing for some early life failures) I suspect it's likely the rest of the device will soon follow and you wouldn't extend it's life by that useful an amount. I don't have hard data however on like the "curve" of flash cell failures as an SSD ages and therefor exactly how much longer you might get based on the minimum to median cell failure.
wtallis 5y ago
A SSD that presents as a traditional hard-drive style block storage device can't shrink itself on the fly without causing catastrophic software problems. The least bad way to implement such behavior would be for the highest-numbered LBAs to be removed first, which means your backup partition table is first to disappear, then you start encountering filesystem corruption. A zoned SSD has an explicit mechanism for the drive retiring zones from service and making them read-only or completely inaccessible. But it's not currently practical to use a zoned storage device as the primary or sole storage in a system; at a minimum you need a regular block device or namespace to boot an OS from.
fomine3 5y ago
https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/over-provisioning-nand-based-ssds-better-endurance-whitepaper.pdf https://www.intel.com/content/dam/www/public/us/en/documents...

verall 5y ago

Generally, you would look to a datacenter line of SSD which is rated for much higher endurance. These are typically overprovisioned much more than consumer ssds in order to meet the endurance requirements. I think most OEMs opt not to let you choose this sort of thing and rather bury it into the drive firmware.

lathiat 5y ago

Theoretically this would be possible but probably wouldn't help much in practice. Writes on an SSD aren't mapped 1:1 from "logical" address to physical address - they constantly balance and move writes around the entire device (the "Flash Translation Layer" it's sometimes called). As a result once you have exhausted the normal reserve capacity (perhaps allowing for some early life failures) I suspect it's likely the rest of the device will soon follow and you wouldn't extend it's life by that useful an amount. I don't have hard data however on like the "curve" of flash cell failures as an SSD ages and therefor exactly how much longer you might get based on the minimum to median cell failure.

wtallis 5y ago

A SSD that presents as a traditional hard-drive style block storage device can't shrink itself on the fly without causing catastrophic software problems. The least bad way to implement such behavior would be for the highest-numbered LBAs to be removed first, which means your backup partition table is first to disappear, then you start encountering filesystem corruption. A zoned SSD has an explicit mechanism for the drive retiring zones from service and making them read-only or completely inaccessible. But it's not currently practical to use a zoned storage device as the primary or sole storage in a system; at a minimum you need a regular block device or namespace to boot an OS from.

fomine3 5y ago

https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/over-provisioning-nand-based-ssds-better-endurance-whitepaper.pdf https://www.intel.com/content/dam/www/public/us/en/documents...