Adiantum: encryption for the low end

Posted Jan 17, 2019 23:57 UTC (Thu) by zyzzyva (guest, #107472)
In reply to: Adiantum: encryption for the low end by jhoblitt
Parent article: Adiantum: encryption for the low end

> Is there any reason not change the `crytsetup` default to be 4K?

(1) Compatibility with old kernels and cryptsetup versions. The 4K encryption sector support is still fairly new, after all.

(2) It's not guaranteed safe on disks with 512-byte sectors, as it can break atomicity guarantees that might be assumed by software. I don't believe this is a problem on modern disks or flash storage, nor on ext4 or f2fs. But the cryptsetup default needs to be more conservative.