it is possible that i could have built a new 9pccpuf after the initial boot of the fs and installed it in place but had never rebooted the machine with the new kernel; but (old age memory failings notwithstanding), i don't think i did that.

FYI, i think i noticed that in ata compatibility mode vid/did is 8086/2920 and in ahci mode it shows 8086/2922. in the version of sources i have, sdata.c checks for the former and sdiahci.c checks for the latter.

On Mon, Aug 19, 2013 at 9:53 AM, erik quanstrom <quanstro@labs.coraid.com> wrote:

On Mon Aug 19 12:25:33 EDT 2013, a@9srv.net wrote:
> Erik's explanation certainly makes sense, but here's an
> alternative possibility. In the past, I've set up the bios on
> a system a certain way, then accidentally written to
> #r/nvram (which isn't really useful on a PC), and had the
> bios reset to factory defaults. Behavior of the bios after
> writing that file is bios-dependent, but it's easy to test.

i happen to have that machine, and i have not seen that
behavior with any version of bios up to 1.2a.

perhaps we haven't written to #r/nvram.

- erik