AHCI driver and static device names

[b. f.]

>  I was getting ready to install the latest FreeBSD 9-RCs image, and I
> found that 9 now defaults to using the ahci driver for sata disks.  This
> would be great if it weren't for the fact that the ahci driver seems to
> do dynamic device name assignment as opposed to the static ones used
> with the older drivers.
>
> I've looked around on google and while this is mentioned (in old
> threads), the "solution" is to use labels or elaborate mapping via hints
> which really aren't solutions imo.  If I have 15 disks in an array, I
> want to be able to label them and know which bay is which device name.
> If I have to replace a drive, I have no idea what dynamic device name it
> will have when it comes time to partition (and label, if I were using
> that).  I could probably figure it out by looking at what disks are used
> on the system, but that's more work that it really should be.
>
> Is there a way to use the ahci driver and get static device names?

cam(4) gives examples of how you can do this by using device hints in
loader.conf(5) or device.hints(5).  Another example:

http://lists.freebsd.org/pipermail/freebsd-fs/2011-March/011036.html

You may need the workaround from:

http://svn.freebsd.org/changeset/base/227635

for some problematic BIOS.  I'm not sure if this is what you meant by
"hints which aren't really solutions", but they seem to be a practical
method for fixing device names with ahci(4).

b.