Why VMware Virtual disk so slow (da0: 3.300MB/s transfers) ?

[Sascha Wildner]

On Sun, 25 Aug 2013 18:44:18 +0200, Dongsheng Song  
<dongsheng.song at gmail.com> wrote:

> [...]
> During the IO test, 'dev_active' changed to about 100.
>
> Then IO speed got much improve, I got 49.0 MB/s with direct IO.
> FreeBSD 9.1 give me 50.5 MB/s with direct IO.
>
> This test confirmed command queue can improve IO performance
> dramatically, thank you very much !

Thanks for reporting and testing. I've pushed it to master and MFC'd to  
3.4.

Sascha