Hurd rumpdisk on real hardware

I've been trying to get a Hurd installation running on a variety of very 
old hardware without success. I want to try some stress tests using 
rumpdisk to see if the disk read/write errors I see sometimes in Qemu 
also occur on hardware.

I built an ext2fs disk image of hurd-i386 using mmdebstrap which when 
dd'd onto a partition using Qemu works normally.  The same image on the 
netbook gets as far as reporting the disk geometry and capabilities 
correctly but the boot log reports nothing further. Running a gnumach 
compiled with --disable-linux-groups (is this valid on i386?) results in 
further progress but only to report a number of lost interrupts of the form:

piixide0:0:0 interrupt lost

[.....] type ata tc_bcount: 4096 tc_skip: 0

I'm not hoping for a specific fix to my particular problem especially 
with so little information presented. I was wondering rather if there 
were any general tips, tricks or guidance to assist me to work it out 
for myself.

Note that I also installed NetBSD 9.4 on the same platform which seems 
to work normally suggesting that the rumplib drivers ought to be 
compatible at least.

Regards,

Mike.