Switched to paravitual scisi adapter – Win2012 will not boot

Long story short, I powered down a vm and incorrectly just clicked LSI logical and changed it to paravirtual. Now after rebooting my windows 2012 vm will not boot properly, I am met with a blue screen saying something went wrong. It defaults into the troubleshooting menu of windows where nothing works as the drive is locked. Is there any way out of this dumb mistake?


Edit: The error given on the BSOD is “Inaccessible Boot Device”

Edit #2: 8Poot with the save, thank you everyone for contributing!

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  1. 8poot is correct in switching back to LSI Logical SAS in order to get the system to boot. Here’s steps to get it working.

    1. Add paravirtual controller to your system along w/ the existing controller.
    2. Add new HD (size is negligible because you’ll be deleting) on paravirtual controller and then boot to Windows. Configure the newly added drive in Disk Management. This installs the paravirtual driver.
    3. Shut down Server and edit VM settings. Move system drive from controller 0 to controller 1 (paravirtual). Remember that System drive needs to be first drive on the controller. You may have to save settings and the re-edit to get the drive order correct.
    4. Boot into Windows. If BSOD then power down and check drive order on paravirtual controller.
    5. After confirming you can boot on paravirtual controller, remove drive configured in step 1 and LSI Logical SAS controller.

    I nearly shat the 1st time this happened. I was lucky to have some good internal VMware support.

  2. First of all what is missing is the pvscsi driver which is not part of the default set of windows server drivers.
    What could work in this case is booting from a windows server iso (provided that you have one available) and access the 2012 server.
    Download the pvscsi driver from VMware for the respective operating system.
    Then use the „dism“ cmdlet to add the driver to the offline 2012 server.
    After that your server should be able to boot again now using the pvscsi driver for the storage part.
    If I am not mistaken, this should work, maybe it helps.

  3. Don’t want this to be a stupid comment…but have you tried to simply change the adapter type back to what u had it previously?

    The issue u are facing stems from a lack of the paravirtual driver in windows. There are easy ways and hard ways of injecting the driver in.

  4. Now that you can boot the machine add a second disk and separate temp controller of pvscsi type. This will allow windows to add the required driver. Then shutdown and swap the primary controller from lsi sas -> pvscsi. That should successfully boot now. Remove the secondary disk and control

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