Re: Waiting for disks to spin up

[Frank Wille <frank%phoenix.owl.de@localhost>]

On Mon, 16 Jan 2012 11:34:50 +0000
Julian Coleman <jdc%coris.org.uk@localhost> wrote:

> When I reboot my DS207 (but not when powering on), it seems that the
> disks spin down and spin up again one after the other.

Do you have any idea why this is happening? I haven't seen that so far.

Why should a disk spin down when a reset-signal is asserted? Or was
it already spun-down before the reset?


> This causes
> altboot (and sometimes NetBSD) to only detect the first disk.

Because the first is faster to spin up again?


> A work
> round for this is to add a delay when checking for disks, as per the
> attached patch.  However, I wondered if there was a better way to do
> this.

I really hope so, that there is a better solution. A 40s delay is
not nice. ;)

First I would check if satapresense() still reports the presence
of a spun-down drive. After that, there is already a loop which tries
to reset the drive ten times, with a delay of one second.

This seems to work when powering on, so it is strange that it fails now.
Some investigation would be interesting. Unfortunately I own no multi-
drive NAS myself.


-- 
Frank Wille