Disk issues on Hyper-V

[David Arroyo]

> I'm not familiar with Hyper-V, but if it emulates several different 
> types of disk controllers it's best to try them all. 

>From what I can tell, Hyper-V provides an IDE controller and a SCSI controller for "generation 1" VMs, and a SCSI controller only for "generation 2" VMs. I've basically tried every permutation of options available in the VM settings.

> When virtualizing, heavy load on the host computer may cause dropped 
> packets in some situations.

This doesn't feel like an issue with load; read/write operations simply do not work at all. There is precious little running on my system. If it were an issue with load I would expect some fraction of operations to succeed intermittently.

What it feels like to me is that there is some windows security "feature" tucked away in the windows registry that is interfering with the way the dragonfly VM wants to access the underlying virtual disk file. The reason I feel this way is that changing the "mode" with natacontrol from WDMA2 to PIO4 allows me to read the disk (but not write).

I suppose what I can try doing is attaching some kind of storage to the system that I can dedicate to the VM, as a test. That might be tricky on a laptop, but I'll look into it.

Along other lines, I could also try other hypervisors. There's virtualbox, and qemu is available for windows. I made a few attempts with qemu on windows, but had similar issues with I/O timing out. I've not tried virtualbox, yet.

David