RFC: ATA to CAM integration patch

[Daniel O'Connor]

On Sun, 28 Jun 2009, Aisaka Taiga wrote:
> Daniel O'Connor wrote:
> > Louis' glabel solution works for me so far :)
>
> I've experienced many weird things while trying to use glabel for
> swap partitions. I wonder where does GEOM store the label, because
> doing
>
> glabel create swap /dev/ad0s1b
>
> successfully adds a label, it shows up on boot:
>
> GEOM_LABEL: Label for provider /dev/ad0s1a is label/swap
>
> however, after a while the label is lost. Maybe the metadata is
> stored in the last sector of the swap space, and the swap data
> overwrites it, I don't know.

I think you want glabel label swap /dev/ad0s1b

'create' is the manual method which won't store any metadata - 'label' 
stores it in the last sector of the provider.

> And the system wants me to enter the root FS name manually because
> ad0 is locked by GEOM and ad0s1a can't be mounted therefore.
> GEOM_LABEL finds the label before GEOM_MIRROR is started properly.
>
> I've experienced this behaviour on both 7.2 and, I think, 8.0 too
> (May snapshot).
> I know we don't really need labels on a gmirror because a gmirror is
> a 'label' in itself and will always appear as /dev/mirror/device-name
> no matter how we swap HDDs and no matter in which order they are
> probed, however this is still a bit strange.

I think if you use label you'd be OK (but you'd need to newfs because 
the created provider is 1 sector smaller). The other alternative is to 
use /dev/ufsid/xxx which won't require a newfs as your existing FS's 
have an ID already (presuming you are using GENERIC).

-- 
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
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