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HyperV Environment Query

  • February 17, 2026
  • 8 comments
  • 40 views

mhakmd

Let me explain the customer environment first.

Customer has 3 Dell Poweredge servers (will name them pe1, pe2, pe3) and 1 Dell Powervault server. Customer uses pe1 and pe2 and has deployed 2 windows machines on them with hyperv on them respectively, pe1 has hyperv1 and pe2 has hyperv2. Customer has taken the storage of these hypervs from the Del Powervault server so that they have a large size. Customer has deployed a windows server on pe3 where veeam has been installed and the backup repository is on that pe3. Now, we added the 2 hyperv on veeam by adding them as standalone hyperv, hyperv 1 has 6 windows VMs under it and hyperv2 has 5 windows VMs under it.
One of the windows VMs is showing a used capacity of 50 GB. Now this windows machine is a file server, has 2 partitions, the C partition where the 50 GB is used , and another Partition, the D partition that has almost 3 TB of files on them.
On Veeam i only see the 50 GB used. 
If i run a backup schedule in order to backup the VM, this means I am only backups up the OS C Partition, so in case of failure I can recovery the C, however all the files will not be backup up and cant be restored? Or am i missing something? In the backup job, if I enable the guest indexing and the application aware processing, will the other hard drive be backup up? Also, why I am i only seeing the C drive not both drives or not the full capacity of the VM?

Another Query,
Now, i was testing the environment, I tried to run a backup job for the file server and it failed with error “Processing VMs with pass-through disks is not supported”, is this because the VMs are taking its storage from Powervault , so it is all given as LUNs to it, preventing it from running the backup on the veeam repository?

As per the documentation :”

  • Pass-through virtual disks and guest disks connected through in-guest FC or iSCSI initiators are not supported for VM backup. VMs with pass-through disks cannot be snapshotted, which prevents snapshot-based backup. In-guest connected disks are skipped from processing automatically. If backup of these VMs/disks is required, use Veeam Agent backup.



What I am suspecting is correct?

Best answer by Chris.Childerhose

Just as the documentation states pass through disks are not supported you would need to use the Agent to backup the other disk on this server.

So I would need to go to each windows server, install veeam agent for microsoft windows for it, then add them in the backup infrastructure as managed servers for microsoft windows?

Yes exactly this if you want to control the backups.

8 comments

Chris.Childerhose
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  • Veeam Legend, Veeam Vanguard
  • February 17, 2026

Just as the documentation states pass through disks are not supported you would need to use the Agent to backup the other disk on this server.


mhakmd
  • Author
  • Comes here often
  • February 17, 2026

Just as the documentation states pass through disks are not supported you would need to use the Agent to backup the other disk on this server.

So I would need to go to each windows server, install veeam agent for microsoft windows for it, then add them in the backup infrastructure as managed servers for microsoft windows?


coolsport00
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  • Veeam Legend
  • February 17, 2026

Hi ​@mhakmd ...as you shared in your original post & Chris re-confirmed...yes, passthrough disks are not supported for backup. So Veeam will not “see” your VM file server volume. The only other way to back up your VM via image-based backup is to either create a large volume on your hyper-v host the VM is on and simply create your VM file server volume from that large hyper-v volume (similar to creating a large datastore in vSphere and creating a large VMDK VM disk to host a file server volume); or, use Veeam Agent for Windows...and in managed mode if you want to have VBR automate backups for you.


Chris.Childerhose
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  • Veeam Legend, Veeam Vanguard
  • Answer
  • February 17, 2026

Just as the documentation states pass through disks are not supported you would need to use the Agent to backup the other disk on this server.

So I would need to go to each windows server, install veeam agent for microsoft windows for it, then add them in the backup infrastructure as managed servers for microsoft windows?

Yes exactly this if you want to control the backups.


mhakmd
  • Author
  • Comes here often
  • February 17, 2026

Just as the documentation states pass through disks are not supported you would need to use the Agent to backup the other disk on this server.

So I would need to go to each windows server, install veeam agent for microsoft windows for it, then add them in the backup infrastructure as managed servers for microsoft windows?

Yes exactly this if you want to control the backups.

Thank you Chris, I did that and run a backup afterwards and it succeeded


Chris.Childerhose
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  • Veeam Legend, Veeam Vanguard
  • February 17, 2026

Just as the documentation states pass through disks are not supported you would need to use the Agent to backup the other disk on this server.

So I would need to go to each windows server, install veeam agent for microsoft windows for it, then add them in the backup infrastructure as managed servers for microsoft windows?

Yes exactly this if you want to control the backups.

Thank you Chris, I did that and run a backup afterwards and it succeeded

Glad to hear that it worked. 👍🏼

 
 
 

coolsport00
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  • Veeam Legend
  • February 17, 2026

Glad to hear using the VAW agent got you working ​@mhakmd 👍🏻


mhakmd
  • Author
  • Comes here often
  • February 17, 2026

Glad to hear using the VAW agent got you working ​@mhakmd 👍🏻

Thank you so much for the help