TRY NOW
book meeting
BACK TO KB LIST

Troubleshooting vPower NFS Datastore Mounting Issues

KB ID: 1055
Product: Veeam Backup & Replication | 12 | 12.1 | 12.2 | 12.3 | 12.3.1 | 12.3.2 | 13 | 13.1
Published: 2011-07-19
Last Modified: 2025-01-02
mailbox
Get weekly article updates
By subscribing, you are agreeing to have your personal information managed in accordance with the terms of Veeam's Privacy Notice.

Cheers for trusting us with the spot in your mailbox!

Now you’re less likely to miss what’s been brewing in our knowledge base with this weekly digest

error icon

Oops! Something went wrong.

Please, try again later.

Challenge

During SureBackup, Instant Recovery, Instant Disk Recovery, or Other-OS FLR operation, the following error is seen in the VMware environment:

Error during the configuration of the host: NFS Error: Unable to Mount filesystem: Unable to connect to NFS server.

or

An error occurred during host configuration.
NFS mount <mount_server>:/VeeamBackup_<mount_server> failed: Unable to connect to NFS server.

The NFS datastore cannot be mounted to the host, so vPower NFS-based restore fails.

If the Veeam vPower NFS Service service is not running on the mount server, or the service is not present because the option "Enable vPower NFS service on the mounter server" is not enabled, the following error will be shown in Veeam Backup & Replication:

Checking if vPower NFS datastore is mounted on host
Failed to publish <vmname> Error: Unable to check if vPower NFS is mounted on the host <esxi_host>
One or more errors occurred.
Failed to connect backup datastore to the ESXi host "<esxi_host>".
Failed to connect to vPower NFS service on host '<mount_server>', port '6161'.

Solution

To know which server to troubleshoot, you must first determine which server acts as the Mount Server for the Backup Repository where the backup files are stored. To find this, edit the repository where the backup files are located. There is a dropdown box on the Mount Server tab designating which server is being used as the Mount Server.
 
*Note: As an isolation step, try changing which server is chosen as the Mount Server in the Repository settings and retry the restore.
Expand the sections below for instructions to complete each troubleshooting step.
1. Make sure the Veeam vPower NFS Service is running on the Mount Server.
Connect to the Mount Server associated with the repository where the backup files are stored, and make sure the Veeam vPower NFS Service is 'Running'.
  • If the service is running, move to the next troubleshooting step.
  • If the service is not running, try to start it. If the service fails to start, review KB1094. After the service begins running again, retry the restore operation.
  • If the service is not present on the mount server, review the Repository configuration in Veeam Backup & Replication and ensure that the "Enable vPower NFS service on the mounter server" option is enabled.
2. Check if another NFS Server software is locking port 111 on the Mount Server.

Connect to the Mount Server and determine if another process is locking the port used by the Veeam vPower NFS Service:

  1. Open an Administrative PowerShell Prompt
  2. Run the following command
Get-Process -Id (Get-NetTCPConnection -LocalPort 111).OwningProcess
  1. Review the output of the command. Either a process will be listed, or an error will be displayed stating that no objects were associated with the port. 
    "Get-NetTCPConnection : No MSFT_NetTCPConnection objects found with property 'LocalPort' equal to '111'.  Verify the value of the property and retry."
Example of Veeam NFS Service locking port correct
Example of what will be seen when Veeam vPower NFS Service is correctly listening on port 111.
4. If a process other than VeeamNFSSvc is listed, you need to either (a) investigate what that product is and stop it from locking the port needed by the Veeam vPower NFS Service, or (b) specify a different Mount Server for the repository.

Example of wrong process locking port 111, specifically Windows NFS Server:
Example of Windows NFS Server running
Example of output when the Windows NFS Server role is enabled and locking port 111.

If VeeamNFSSvc is listed as locking port 111, move to the next troubleshooting step.

If not, resolve port conflict and retry the restore.

3. Remove previously used vPower NFS Datastores marked as (Invalid) in the vSphere Environment.
Review the list of Datastores listed in the vSphere Environment and unmount any which begin with "VeeamBackup_" and are marked as (Invalid) or (inaccessible).
example of inaccesible datastore

If there are no datastores matching the description provided, move to the next troubleshooting step.

If there were, and you have unmounted them, retry the restore operation.

4. Test if the Mount Server can ping the VMkernel Port of the ESXi host specified during the restore.
Connect to the Mount Server associated with the repository where the backup files are located. Then, ping the VMkernel port of the ESXi host specified during the restore operation. There may be multiple VMkernel ports, test the one that is in the same network segment as the Mount Server. The ping must be successful.
1. Within a vSphere Client, select the ESX(i) host specified during the restore operation.
2. Go to the Configure tab
3. Within the Networking section, click VMkernel adapters
4. Note the IPs list for each VMkernel adapter
5. Ping the VMkernel IP that is in the same network segment as the Mount Server.
screenshot shows how to identify vmkernel port list under configure section of host in vsphere client

If you can ping the ESXi host's VMkernel Port IP from the Mount Server, move to the next troubleshooting step.

If the ping fails, resolve the connectivity issue and retry the restore operation.

It is possible to determine which ESXi host IP addresses Veeam Backup & Replication has discovered by searching the log file Svc.VeeamBackup.log for line entries that contain [CHostHelper]. The Svc.VeeamBackup.log file is located on the Veeam Backup Server and is stored by default in C:\ProgramData\Veeam\Backup.
5. Test if the ESXi host can vmkping the Mount Server.

Connect to the ESXi host specified during the restore operation using SSH and confirm that the host can vmkping the Mount Server associated with the repository where the backup files are located.

The steps above may require that you Enable Acces to the ESXi Shell.

If no connectivity issues were identified, move to the next troubleshooting step.

If there were connection issues, resolve them and then retry the restore operation.

6. Check the ESXi host directly, and remove old 'VeeamBackup_' Datastores.
In rare instances, the ESXi host may retain information about a previously connected 'VeeamBackup_' datastore. When this occurs, Veeam Backup & Replication will fail to create a new datastore with an error message similar to: 
Unable to mount vPower NFS volume (<mountserver_ip>:/VeeamBackup_<mountserver>). Fault "AlreadyExistsFault",
Error The specified key, name, or identifier already exists.
Unable to create datastore VeeamBackup_<mountserver_ip> on host <esxi_host>, because it already exists
Failed to add NFS datastore for NFS host, Failed to mount NFS volume

Review the steps detailed in KB1690 to remove existing VeeamBackup_ datastore entries and restart ESXi Management Agents.

Review the steps detailed in KB4167 to review and remove cached VeeamBackup_ datastore entries.

If the steps in KB1690 and KB4167 did not result in the restore working, move to the next troubleshooting step.
7. Test restore with vPower NFS IP Authorization disabled. (VBR 9.5 U4 or newer)

Starting with Veeam Backup & Replication 9.5 U4, the Veeam vPower NFS Service uses an IP allowlist to control which servers can connect to the NFS share. In some rare cases, Veeam Backup & Replication may not add the IP address of the ESXi host to the IP allowlist.

To isolate whether this is occurring, it is possible to disable the IP authorization control system by creating the following registry value on the Mount Server.

Please note that this value disables built-in IP authentication for vPower datastore and is only recommended for testing purposes.

Key Location: HKLM\SOFTWARE\WOW6432Node\Veeam\Veeam NFS\
Value Name: vPowerNFSDisableIPAuth
Value Type: DWORD (32-Bit) Value
Value Data: 1

After creating the above registry value, restart the Veeam vPower NFS Service.

Retry the restore operation with the above registry value in place on the Mount Server associated with the repository where the backup files are located.

If the restore works with the IP Authorization disabled, contact Veeam Support. We can assist in determining what IP was used to connect to the vPower NFS Share and why it was not automatically added to the allowlist previously.

If the restore still fails, remove the registry value, restart the Veeam vPower NFS Service, and move to the next troubleshooting step.

It is possible to determine which ESXi host IP addresses Veeam Backup & Replication has discovered by searching the log file Svc.VeeamBackup.log for line entries that contain [CHostHelper]. The Svc.VeeamBackup.log file is located on the Veeam Backup Server and is stored by default in C:\ProgramData\Veeam\Backup.
8. Test manually mounting the Veeam vPower NFS Datastore
Follow the steps detailed in KB1284 to test manually adding the 'VeeamBackup_' datastore.

If the 'VeeamBackup_' datastore could be manually added to the ESXi host, retry the restore operation, making sure to specify the same ESXi to which the datastore was able to be attached.

If the 'VeeamBackup_' datastore could not be manually attached, and you have reviewed all other troubleshooting steps, a much deeper investigation will be necessary. Such analysis may require that you create a case with VMware Support so that a three-way conference call can occur with a VMware Engineer reviewing the logs in the vSphere Environment to help determine why the NFS datastore could not be created.

More Information

Related Articles

If this KB article did not resolve your issue or you need further assistance with Veeam software, please create a Veeam Support Case.

To submit feedback regarding this article, please click this link: Send Article Feedback
To report a typo on this page, highlight the typo with your mouse and press CTRL + Enter.

Spelling error in text

Thank you!

Thank you!

Your feedback has been received and will be reviewed.

Oops! Something went wrong.

Please, try again later.

You have selected too large block!

Please try select less.

KB Feedback/Suggestion

This form is only for KB Feedback/Suggestions, if you need help with the software open a support case
By submitting, you are agreeing to have your personal information managed in accordance with the terms of Veeam's Privacy Notice.
Verify your email to continue your product download
We've sent a verification code to:
  • Incorrect verification code. Please try again.
An email with a verification code was just sent to
Didn't receive the code? Click to resend in sec
Didn't receive the code? Click to resend
Start using Veeam:
Download the product
&
Activate the license key
Thank you!

Thank you!

Your feedback has been received and will be reviewed.

error icon

Oops! Something went wrong.

Please, try again later.