IBM blade server abysmal disk write performances

[Wojciech Puchar]

>> 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.)
because they are only raw devices. caching is in filesystem.