On Wed, Mar 28, 2018 at 02:43:27PM -0500, Eric Blake wrote:
Setting the preferred size to >= min(min_size, 4k) doesn't make
sense (a preferred size of 4k when min_size is 64k means that
you get efficient I/O when requesting something smaller than
the minimum granularity?). Fix it by documenting the intended
semantics that the preferred size is >= max(min_size, 4k).
Thanks, that does seem like an improvement.
Side note: there are still hard disks out there which use 512-byte
blocks[1]. It would make sense for an nbd server exporting a raw hard
disk with 512-byte blocks to use that as the preferred size.
What was the reasoning we used originally for clamping that to 4k at
minimum?