Subject: Re: wedges and hotplugging
To: None <current-users@netbsd.org>
From: Blair Sadewitz <blair.sadewitz@gmail.com>
List: current-users
Date: 11/14/2006 17:16:52
This will not help in my case--at least I don't think--because sd4
only appears if the flash drive is plugged into the USB port.  If it's
not, there is no device to pin down.  If the device is plugged in, a
wedge (dk device) is configured for it.  My flash card reader gets
probed as sd0-sd3, so if I insert cards in there, those get wedges,
too.  All of this autoconfiguration messes up the wedge assigments to
my fixed disks, which borks their assignment in fstab; and then I
can't boot to multiuser mode!

IMHO, this is significant concern re: the wedge implementation, unless
in the future things will be done differently. If there's something
I'm missing here, I request enlightenment/admonition.

Regards,

--Blair



On 11/14/06, gabriel rosenkoetter <gr@eclipsed.net> wrote:
> On Tue, Nov 14, 2006 at 02:54:09AM -0500, Blair Sadewitz wrote:
> > Let's say that I'm using wedges and I want to use USB flash drives and
> > a USB CF card reader.  If I boot the machine with any cards or flash
> > drives connected, it screws up the order in which wedges are
> > autoconfigured.  Does anyone know how I could work around this?
>
> The canonical way to force an order on device detection is to
> specify it explicitly in the kernel config. I'm not sure of the
> various drivers involved for the devices you describe, but here's an
> example from a kernel config for a machine I don't use any more:
>
> sd0 at scsibus0 target 0 lun 0  # 2 GB LFS disk
> sd1 at scsibus0 target 1 lun 0  # 6 GB boot disk
> sd* at scsibus? target ? lun ?  # SCSI disks
>
> (I don't remember why I thought it was necessary to pin these
> down, nor why I decided I wanted the boot disk to be sd1 rather than
> sd0, but that's not really the point here.)
>
> --
> gabriel rosenkoetter
> gr@eclipsed.net
>
>


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