Hyper-V Program Manager
Over the weekend, I attempted to reconfigure some of the drives in my Hyper-V server at home. Note that I said “attempted”. I ran into hardware issues and ended up having to revert back to my old configuration - but somehow in all of this – I broke my system disk.
Specifically it would not boot any more.
This did not phase me because I knew that the excellent startup repair tool in Windows would soon have me up and running – which it did.
But I was surprised to find that when my system did finally boot – none of my virtual machines started up. When I tried to start the virtual machines manually, I was informed that the hypervisor was not running.
After scratching my head for a moment, I realized what had happened. Startup repair had rebuilt my boot configuration data store to get my system up and running. But it did not know that Hyper-V needs to have some specific settings enabled in the boot configuration data store in order to start the hypervisor.
I quickly opened an administrative command prompt and ran the following command:
bcdedit /set hypervisorlaunchtype auto
After that I rebooted the system and successfully started my virtual machines.
Cheers, Ben
good to know. i'll file this in my head. thanks
If the system doen's boot anymore, how can you launch the Startup Repair Tool?
Thanks
About boot configuration data store, i use this scripts
# creating a new VHD boot entry
# -------------------------------------------------------
$description = 'Windows 7 from VHD'
$vhd_path = 'vhds\win7entx64.vhd'
bcdedit.exe /export ".\bcd_backup.bcd"
$res = bcdedit.exe /copy '{current}' /d $description
$id = $res.Split('{}')[1]
bcdedit.exe /set "{$id}" device vhd=[locate]\$vhd_path
bcdedit.exe /set "{$id}" osdevice vhd=[locate]\$vhd_path
bcdedit.exe /set "{$id}" detecthal on
"{$id} entry created!"
bcdedit | out-file .\newentry_log.txt
# creating a new Boot Entry
$description = 'Windows Server 2008 R2'
bcdedit.exe /set "{$id}" device partition=E:
bcdedit.exe /set "{$id}" osdevice partition=E:
bcdedit.exe /set "{$id}" hypervisorlaunchtype auto
Cheers,
Luciano
jim Philips -
You can run the startup repair tool off of an install DVD - which is what I did in this case.
Ben
Hi Ben,
I see that hyper-V is supported with sysprep.
You have to recreate the bcd entry when you apply the image but i want to know if the Mac address pool is regenerated ?
Very informative info since I'm new with Hyper-V virtual machines..
so simple solution yet so hidden.. u are the guy!!! cheers!! i now love you! Lol i was about to call DELL and bash them for selling me a bad laptop!
You sir are a genius... been trying to find something "on the google" about this issue for the better part of 4 hours. I lost our BCD store after a raid controller failure. After finally getting up and running after using the r2/win7 boot up repair I found that none of my VM's would spin up (I was only running a test machine and that pesky BES 5.0 on a little app instance).
Thanks again!
Thanks a lot. You saved my life. I had exactly the same issue. Now its working again.
I had that problem too and it fixed it... THANKS
I added disks array to one of my Hyper-V, and run in the same issue (as HDD boot order has changed in the BIOS).
After a Startup Repair, same issue than yours: an EventID: 3112.
Your tip saved me. Thanks.
For everybody, a repaired boot entry in BCD has its description field ending with " (recovered)". So, if you have the issue and a "bcedit /enum" shows this addition in description, Ben's tip will make the job.
Thanks.
Thank you, bcdedit helped me to get my vm's starting again after i had to recover my hyper-v host.
Thanks, this really saved me a compleate reinstall and configuration of Server 08 R2.
Thanks, I got the same issue but with Windows 8 and it's integrated Hyper-V.
Just had the exact same problem after flashing bios on a server which did something funny with the raid config and required a bootrec /fixmbr to get back into windows.
I'd been assuming that the BIOS flash was having compatability issues with VT'd, until I realised that the BCD was wiped!