Help creating Windows VM using answer file (error: "Windows could not apply the unattend answer file")

[Adakis]

Hi,

I'm a first time Proxmox user after being a long time VMWare user so please be gentle . In my VMWare environments, I had a custom Windows ISO I built with an answer file that would automatically create/partition the C drive, install updates, etc. I installed the latest Proxmox on a NUC yesterday and attempted to create my first VM using my custom Windows ISO, and it fails immediately with:



I found this thread (https://forum.proxmox.com/threads/problem-with-windows-vm-creation.136711/#post-612363) which mentions this error, but it seems that individual just went the route of using a vanilla Microsoft Windows ISO to get around the problem.

Long story short, I'm trying to figure out if custom ISOs should work fine in Proxmox, or if they're simply not supported and I'm going to have to build all my Proxmox VMs from scratch (I'm reaaaaaallllly hoping that's not the case).

P.S. - if I do use a vanilla Windows ISO the install does continue/complete just fine.

Thanks,
Adakis

 

[bbgeek17]

There is nothing in Proxmox today that is aware of what "custom windows ISO" is, or an "answer" file. It's just and ISO/file to PVE. So it should "just work".

Given that it's Windows, I suspect you are using the UEFI bios? If you do, there is a known issue between the UEFI and an IDE CD device. One must use an SCSI chain.

That presents an issue, as Windows does not recognize VirtIO SCSI without additional drivers. You may be able to overcome this by building a Custom Windows image that includes VirtIO drivers.

Good luck

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[bbgeek17]

Just realized that the error message actually seems to imply that the answer file was read and its the "Disk Configuration" setting that did not work.
If that is the case, it could still be a driver issue. Or, perhaps, the actual disk configuration is not matching what is in the answer file. Do you have any debug tools available to you?

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[Adakis]

Hey thanks so much for the help. I took my custom ISO and followed Microsoft instructions (https://learn.microsoft.com/en-us/w...s-to-an-offline-windows-image?view=windows-11) to add VirtIO drivers. I went overkill and just added EVERY driver from the extracted VirtIO folder to the master image. I uploaded to Proxmox box and tried to boot again but got same error.

So I think for now I'll go the route of seeing if there are answer file tweaks I need to make. Will report back with what I find.

 

[Adakis]

Hello,

For future travelers, my problem was the <DiskConfiguration> settings in my unattend file. Making the config more vanilla got my auto install working:

<DiskConfiguration>
                <Disk wcm:action="add">
                    <CreatePartitions>
                        <CreatePartition wcm:action="add">
                            <Order>1</Order>
                            <Size>500</Size>
                            <Type>Primary</Type>
                        </CreatePartition>
                        <CreatePartition wcm:action="add">
                            <Order>2</Order>
                            <Type>Primary</Type>
                            <Extend>true</Extend>
                        </CreatePartition>
                    </CreatePartitions>
                    <ModifyPartitions>
                        <ModifyPartition wcm:action="add">
                            <Active>true</Active>
                            <Format>NTFS</Format>
                            <Label>systemofadown</Label>
                            <Order>1</Order>
                            <PartitionID>1</PartitionID>
                        </ModifyPartition>
                        <ModifyPartition wcm:action="add">
                            <Format>NTFS</Format>
                            <Label>SeaDrive</Label>
                            <Letter>C</Letter>
                            <Order>2</Order>
                            <PartitionID>2</PartitionID>
                        </ModifyPartition>
                    </ModifyPartitions>
                    <DiskID>0</DiskID>
                    <WillWipeDisk>true</WillWipeDisk>
                </Disk>
                <WillShowUI>OnError</WillShowUI>
            </DiskConfiguration>

 

[peini7]

Hi,
i'am currently struggling with the same error, trying to build a packer config for setting up Windows Server 2022.
I tried your DiskConfiguration but still get the same error.

Can you please tell me your hardware configuration in Proxmox?
Especially for the drives?

 

[peini7]

Got it working. This helped me a lot.
https://www.tenforums.com/tutorials...utomated-unattended-install-windows-10-a.html

 

[Adakis]

Hey @peini7 I actually would appreciate if you could share YOUR configuration. When I saw your first reply I went and tried to stage another Win 10 boot using the unattended, and it failed! After a bunch of troubleshooting I found that I had originally setup an IDE drive and installed to that. But if I use the Virtio SCSI like Proxmox recommends, my install fails and I have to basically strip ALL disk config information from my XML to get it to work.

So if you have a working config for unattended (that you can sanitize) I’d love to see it - specifically the disk config and whether you loaded the Virtio driver on the fly, etc.

Thanks!

 

[peini7]

I zipped you together my work in progress configuration, but i'am using Windows Server 2022.
Please note that some files are not used as i'am currently playing arround.

 

[Adakis]

Thanks I'll have a look, much appreciated!