restore(8)ing new / -- boots on metal but not in a VM

Tim Judd tajudd at
Tue Oct 13 18:42:24 UTC 2009

On 10/12/09, Alex Jurkiewicz <alex at> wrote:
> 2009/10/13 Tim Judd <tajudd at>:
>> Is the virtual machine using SCSI emulation to boot, or is it using IDE?
>> SCSI drives are da(4), IDE drives are ata(4) [aka ad(4)]
> The dump was taken from an ad0 device on physical hardware, and I'm
> attempting to restore to the same, just on virtual hardware.
>> If the boot blocks (maybe boot0 specific) point to an ad/ata device,
>> and the virtual machine is SCSI, it won't find the boot sectors.
> So, if I make a dumpfile of / on an ad(4) device, I can't restore it
> to a da(4) device and expect it to boot? I guess at minimum I'll need
> two copies of this image if I want to roll it out on machines with
> both sorts of drive, right?
> Thanks,
> AJ

That's part of my point, I don't run with boot0, so it may be one of
it's features.

My suggestion is to check the VM config and see if you can emulate an
IDE ad(4) device instead of the possible SCSI da(4) device that
vmware/virtualbox may setup.  I'm almost positive (not 100% because I
don't have either one of those installed at the moment) that both
those products default to a SCSI device.

Let us know.

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