>> What's more (in relation to our long term data integrity aim) >> order of magnitude for their unpowered data retension period is >> 1 YEAR. (Read it as 6months to 2-3 years.
> Does btrfs need to date-stamp each block/chunk to ensure that data is > rewritten before suffering flash memory bitrot? > Is not the firmware in SSDs aware to rewrite any too-long unchanged data? No. It is supposed to handled by firmware. That's why they should be powered. It is not visible to the file system. You can do a google search with terms "ssd data retension". There is no concrete info about it. But figures range from: - 10 years retention for new devices to - 3-6 months for devices at their 'rated' usage. Seems there is consensus about 1 year. And it seems SSD vendors are close to the datacenters. Its todays tech. In time we'll see if it will get better or worse. In the long run, we may have no choice but to put all our data in the hands of belowed cloud lords. Hence the NSA. :) Note that Sony has shutdown its optical disc unit. Regards, Imran -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
