Re: Trouble swapping bootdisk to different controller

[Heinrich Rebehn <rebehn@xxxxxxxxxxxxxxxxx>]

Joerg Sonnenberger wrote:
> On Mon, Jan 31, 2005 at 12:27:17PM +0100, Heinrich Rebehn wrote:
>
> > After adjusting the BIOS boot config, the kernel asked me where to mount 
> > the root fs from. After some probing, i figured out it was ufs:ad7s2a.
> > Of course the kernel count not mount the remaining fs because fstab was 
> > still referring to ad0s2*.
>
>
> This means that the boot loader and the kernel can't figure the correct
> mapping out. You can override it in at the loader prompt by setting
> vfs.root.mountfrom to the correct slice. But playing a bit more with
> the BIOS settings may fix it.
>
>
> > Some of the obstacles i experienced:
> > - /sbin not in PATH, why?
>
>
> It's a fallback value built into the shell and that doesn't
> include /sbin. Just add it.
>
>
> > - vi not available
>
>
> vi is on /usr, that's expected.
>
>
> > - keyboard layout not set (i use german keyboard, luckily i am quite 
> > familiar with the US layout)
>
>
> kbdcontrol is on /usr, too. The normal rc scripts haven't been
> run yet to customize the keyboard layout, so this is expected.
>
>
> > - weird device numbering: why can't the first disk be assigned to ad0???
>
>
> Because you have ATA_STATIC_ID in your kernel? Because the kernel doesn't
> know which "the first disk" is? Normally "internal" controllers are probed
> before "external" controllers, therefore "internal" disks are enumerated before
> "external" disks. Combine this with ATA_STATIC_ID and you get the behaviour
> you have.
Yes, it is in GENERIC. I wil try removing it.
> > - I then decided to try and edit fstab with sed (of course sed was not 
> > there), but it would not have helped me anyway, because the root fs was 
> > mounted -ro.
> > I then tried to remount the root fs -rw:
> >
> > # mount -u -rw / ==> /dev/ad0s2a not configured
> > # mount -u -rw /dev/ad7s2a / ==> /dev/ad7s2a: No such file or directory
>
>
> Now you have a small problem :) We normally don't create device entries
> for secondary slices. Workaround:
> mount -t mfs swap /mnt
This even worked although no swap was set up
> cp /dev/MAKEDEV /mnt/
> cd /mnt
> sh MAKEDEV ad7s2
  sh MAKEDEV ad7s2a	(Just for the records :-) )
> mount -uw /dev/ad7s2a /
  mount -uw /mnt/ad7s2a /  ( dto. )
> cd /dev
> sh MAKEDEV ad7s2
>
> Joerg

Thanks for your help Joerg. Good to know that help is also available in 
the same timezone ;-)

And, more important: the SCSI-RAID is accessable now !!! :-)
Will test performance later this evening..

--Heinrich