IBM blade server abysmal disk write performances

[Dieter BSD]

I wrote:
> The kernel must be doing write-behind even to a raw disk, otherwise
> waiting for write(2) to return before issuing the next write would
> slow it down as Matthew suggests.

And a minute after hitting send, I remembered that FreeBSD does not
provide the traditional "raw" disk devices, e.g. /dev/rda0 with an 'r'.
(Now if I could just remember *why* it doesn't.)