Aside from the other comments, I'll add that aac(4) was disabled because it was buggy and Adaptec wouldn't provide documentation. Theo was quite clear about this at the time, see the 3.8 release notes.
Ok, I remember about situation with Adaptec... But what with "isp" driver (from FreeBSD)? After some "researches" I think that aac(4) is not the way for ServeRAID 4M, but "isp" is. -- engineer
