ZFS root on MB Intel S3420GP

[Jeremy Chadwick]

On Sun, Apr 17, 2011 at 10:45:38PM +0400, Lystopad Olexandr wrote:
>  Hello, Jeremy Chadwick!
> 
> > > > With regards to AHCI mode: Most of us strongly advocate use of ahci.ko
> > > > (not ataahci.ko; they differ), which does SATA<->CAM translation.  You
> > > > also gain NCQ capability using this.  Be aware your disks will appear as
> > > > "adaX" (not a typo), and you will use "camcontrol" (rather than
> > > > "atacontrol") to maintain them.  Utilities like smartmontools do work
> > > > with this.  Many of us (users and developers) have been using ahci.ko
> > > > reliably for 1-2 years now.
> > > 
> > > Simply add ahci_load="YES" in loader.conf? Or something else?
> > 
> > Correct.
> > 
> > I tend to do the following from the very beginning of a new FreeBSD box
> > installation, however:
> > 
> > - Boot FreeBSD installation medium (PXE, CD, USB, whatever)
> > - At beastie menu, escape to loader prompt and do "load ahci" then
> >   "boot"
> > - Install FreeBSD like usual, creating slices/partitions on adaX disks
> >   like normal, etc...
> > - When the system reboots, at the beastie prompt, make sure to escape to
> >   loader and do "load ahci" then "boot" again.
> > - Once the system is finally up, edit /boot/loader.conf to add
> >   ahci_load="yes".
> 
> What about ahci_load="YES" after freebsd install? Is it too late?

I don't recommend enabling ahci.ko after the OS has already been
installed on an adX disk, simply because I believe the combination of
GEOM+CAM+ahci may show different geometry details than GEOM+ata would.

Note: I said "I believe", not "I can confirm/validate".  I could be
completely wrong.  Rather than find out ( :-) ) I tend to try and do
things consistently from the very beginning.

So you can try it if you want, be my guest, report back.

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.               PGP 4BD6C0CB |