Hello All,

 

I'm passing through my SSD (OCZ Vertex 3) for use as a Windows VM. Runniug unRAID 6.1.9.

 

Everything works fine, EXCEPT that I have performance issues. I want to keep my unRAID setup as is (running several different OS). That is, I can boot the OCZ Vertex 3 drive with Windows 7 as the HOST (NOT running unRAID), so I believe that it is an issue with my unRAID configuration. I'm using i440-fx2.3. It BSODs with error code 0x7B and tells me to run chkdsk /F when booted as a VM (AHCI enabled in Windows 7 registry). If I enable IDE mode, it can boot as a VM or as a host, but obviously the performance issues arise. Of course, my BIOS is configured to enable AHCI mode. This is a P2V. CPU: AMD FX-8120

 

I suspect that the performance issues arise from a very long boot time all thanks to IDE, since in AHCI mode as Windows 7 host it boots in maybe 5 seconds vs 2 minutes.

I'd like to emphasize that I wish to enable AHCI mode to get as much performance out of the SSD allowable by AHCI and small cost of virtualization. I changed from bus='ide' to bus='sata' hoping that it would help, but again I can only boot as a VM with IDE drivers enabled rather than AHCI drivers. I have a different VM (OS X) working flawlessly. It boots from a 7200RPM HDD faster than this SSD boots in IDE mode as a VM (30 seconds vs 2 minutes).

 

To clarify:

This works:

                  Windows 7 VM,    IDE mode

                  Windows 7 HOST, IDE mode

                  Windows 7 HOST, AHCI mode

This doesn't work:

                  Windows 7 VM,    AHCI mode

 

This is the same SSD used for all of these 4 setups. I tweaked the registry values as appropriate to switch between AHCI and IDE.

 

Here is the relevant part of my configuration:

 

<devices>
    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='writeback'/>
      <source dev='/dev/disk/by-id/ata-OCZ-VERTEX3_OCZ-***********'/>
      <backingStore/>
      <target dev='hdc' bus='sata'/>
      <alias name='sata0-0-2'/>
      <address type='drive' controller='0' bus='0' target='0' unit='2'/>
    </disk>

 

I would GREATLY appreciate any help.

 

Thank you.

Force install the virtio storage drivers in your windows 7. That 7B error is a result of not having the correct drivers installed.

Thank you.

 

Oops. I corrected the 7B error earlier today (framebuf). It is apparently caused by passing through GPU without having VirtIO drivers installed.

 

However, there is still BSOD when trying to run the VM with AHCI drivers as opposed to IDE.

When it boots as a VM, why is it ungodly slow. Is it due to QEMU using IDE? Is it correctable?

 

I found this: http://forum.osdev.org/viewtopic.php?f=1&t=26483 (last comment)

 

 

I've imaged the whole thing for data later.

 

If somebody knows the solution, please share. I'm going on vacation for a week and a half but I will be checking.

 

If no easy solution is found, I'll just install a VM from scratch.