[Qemu-devel] Problem installing NT4 under QEMU 0.9.1 - IDE driver error under high load?

[Mark Cave-Ayland <mark.cave-ayland@siriusit.co.uk>]

Hi there,

I've been trying to install NT 4.0 workstation on a local qemu 0.9.1 
instance under Linux x86_64, and I believe that I have come across an 
error within the IDE driver under high load.

My initial process was as follows:


1) Image the installation CD on my local machine; this was to speed up 
the installation process
	dd if=/media/cdrom of=winnt4.img bs=1024

2) Create a new disk image
	qemu-image create ntfs.img 2G

3) Fire up qemu and run the install:
	qemu-system-x86_64 -hda /home/images/ntfs.img -cdrom
	winnt4.img -vnc localhost:11 -no-acpi -win2k-hack -boot d

4) Run through the NT4 installation process

5) Reboot


Upon reboot, I get a BSOD and errors about files being corrupted on the 
partition. However the error goes away, and the install completes fine 
after the reboot if I use the cdrom directly, i.e. I run qemu like this:

qemu-system-x86_64 -hda /home/images/ntfs.img -cdrom
	/dev/hda -vnc localhost:11 -no-acpi -win2k-hack -boot d

If I execute 'md5sum winnt4.img' and 'md5sum /dev/hda' then I get back 
the same MD5 hash for both the physical CDROM copy and the local CD 
image, so I am fairly sure the local CD image is not corrupt. I have 
also tried with/without -win2k-hack and it doesn't seem to make a 
difference.

My theory is that there is some form of race condition in the IDE driver 
  related to the transfer speed. When using the local winnt4.img CD 
image, the installation is very quick, but the resulting file system 
appears to be corrupted. When I use the real CD inserted into /dev/hda, 
the installation is much slower but the file system appears fine.

Has anyone else experienced similar symptoms during normal QEMU usage?


Many thanks,

Mark.

-- 
Mark Cave-Ayland
Sirius Corporation - The Open Source Experts
http://www.siriusit.co.uk
T: +44 870 608 0063