[dm-devel] [PATCHv5 00/14] dm-zoned: metadata version 2

[Martin K. Petersen]

Damien,

> Any idea why the io_opt limit is not set to the physical block size
> when the drive does not report an optimal transfer length ? Would it
> be bad to set that value instead of leaving it to 0 ?

The original intent was that io_opt was a weak heuristic for something
being a RAID device. Regular disk drives didn't report it. These days
that distinction probably isn't relevant.

However, before we entertain departing from the historic io_opt
behavior, I am a bit puzzled by the fact that you have a device that
reports io_opt as 512 bytes. What kind of device performs best when each
I/O is limited to a single logical block?

-- 
Martin K. Petersen	Oracle Linux Engineering