Quoting Paul Sijben,

> I recently aquired an old 486 system with a Quantum 270A IDE disk.

> I tried putting NetBSD on it using the boot floppy 1.2G. It failed during
> the population with bootstrapping binaries.

> I saw a panic message and the system rebooted.

> I have put the disk in another system with a GENERIC 1.2G kernel. (and the bootstrapping binaries) 

> There it shows the same behavior. The GENERIC kernel does not reboot immediately 
> after the panic so I could write it down,
> the panic reads: 
> mode = 020640 inum=3328 fs=<mountpoint of the disk>

> panic: ffs_valloc: dupalloc

[..]

One cause of such panics has recently been fixed (july 7th), so make sure
that you try kernels more recent than that date. However, that particular
bug should not show up so easily..

If the problems are still there even if you are using a post-july 7 kernel,
perhaps you could mail some more info about your system, like disk
geometry, what the disklabel says, does the disk work fine under other
systems, etc.

- Frank