4 ms·
How does APFS prevent bitrot? I thought it doesn’t do checksumming and error correction, and instead passes this task on to the SSD’s memory controller.
by tqkxzugoaupvwqr 9y ago
How does APFS prevent bitrot? I thought it doesn’t do checksumming and error correction, and instead passes this task on to the SSD’s memory controller.
- dilap 9y agohmm, actually, i just sort of assumed it would fix the bitrot issue! that would be bad if it didn't...
- danieldk 9y agoIt checksums metadata [1]: http://dtrace.org/blogs/ahl/2016/06/19/apfs-part5/ http://dtrace.org/blogs/ahl/2016/06/19/apfs-part5/ From the same article: the engineers contend that Apple devices basically don’t return bogus data. NAND uses extra data, e.g. 128 bytes per 4KB page, so that errors can be corrected and detected. (For reference, ZFS uses a fixed size 32 byte checksum for blocks ranging from 512 bytes to megabytes. That’s small by comparison, but bear in mind that the SSD’s ECC is required for the expected analog variances within the media.)
- dilap 9y agowow, that's very disappointing.