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vPower NFS Troubleshooting Mounting Issues

KB ID: 1055
Product: Veeam Backup & Replication
Version: All
Published: 2011-07-19
Last Modified: 2020-08-13
Languages: DE | IT | FR | ES


During SureBackup, Instant Recovery, or Other-OS FLR operation, you receive the error: 

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

The NFS datastore cannot be mounted to the host, so vPower NFS based restores fail.


There are several possible causes for this:

  • The Veeam vPower NFS Service is not started. (
  • The Veeam server is on a subnet that does not have access to a VMkernel port on the ESXi host.
  • The Veeam server cannot reach the VMkernel port on the ESXi host due to a firewall configuration.
  • Datastores within the environment that appear as (Invalid).
  • An issue within the VMware environment is preventing the NFS datastore from being mounted.


In order to know which server to troubleshoot, one must know which server is acting as the vPower NFS server for the repository. To find this edit the repository for the backup files to be used in the restore. On the ‘vPower NFS’ tab there is a dropdown box designating which server is being used. The server listed is where the troubleshooting must be performed from.
*Note: An isolation step can be to try changing which server is chosen as the vPower NFS server in the Repository settings.
If the vPower NFS service is not running on the server designated within the repository settings, please review:
The following is a list of common troubleshooting steps


  • Testing for connectivity to and from VMkernel Port

Test from vPower NFS server to VMkernel port:
1.       Within a vSphere Client select the ESX(i) host that the NFS Datastore is being connected to.
2.       Go to the Configuration Tab
3.       Go to the Networking section
4.       Look for a VMkernel port, and note its IP
5.       Ping the VMkernel port from the vPower NFS server

 Test from VMkernel port to vPower NFS server
1.       Connect to the ESX(i) host that the NFS datstore is being connected to via SSH**
2.       Using the vmkping command to test connectivity to the vPower NFS servers

  • Remove “(Invalid)” datastores:

Within a vSphere Client check the Configuration>Storage section of each host for datastores starting with “VeeamBackup_”, specifically ones that show up in italics with (Inactive). Unmount each of these and try the restore or mount procedure again. 

  • Test adding the NFS Datastore manually ( For Veeam Backup & Replication 9.5 Update 4 and later please refer to the More Information section for additional settings required for testing.

1.       Within a vSphere Client select the ESX(i) host that the NFS Datastore is being connected to.
2.       Goto the Configuration Tab
3.       Goto the Storage section
4.       Click Add Storage…
5.       Select the radio option for ‘Network File System’
6.       For “Server”, enter either  the IP or Hostname of the vPower NFS Server
7.       For “Folder”, enter “/VeeamBackup_<servername>”  servername is the NetBIOS name of the vPower NFS Server. If your vPower NFS server is added by IP, you need to specify VeeamBackup_XXX.XXX.XXX.XXX
8.       Do not check the box for Mount NFS read only
9.       Enter in to the Datastore name the same as folder without the starting forward slash. i.e. “VeeamBackup_<servername>”
10.   Click next and complete the process.


  • Known Issue: “Unable to Mount VPower NFS Specified Key Name or Identifier Already Exists”

Please review:


  • Known Issue: Another service is locking a port needed by vPower NFS:
    1. Open an Administrator Command Prompt
    2. Run the following commands
         netstat -bona > portlist.txt
        notepad portlist.txt
    3. Search the text file and confirm that the following ports are not locked by another process.


More information

With new security enhancements in Veeam B&R 9.5 Update 4 it is no longer possible to mount vPower NFS datastore manually to an arbitrary server. To be able to perform this test, add vPowerNFSDisableIPAuth (DWORD) = 1 registry value to the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Veeam\Veeam NFS\ and restart Veeam vPower NFS Service.
Please note that this value disables built-in IP authentication for vPower datastore and is only recommended for testing purposes.

**SSH may be disabled on your ESXi host. Below are directions to enable SSH on host so that you may connect and use the vmkping command as part of the troubleshooting steps above.
Note: Veeam's vPower NFS does not require SSH to be enabled on the host, please remember to disable SSH after testing with vmkping.

1.  To enable SSH from the vSphere Client
2.  Select the host and click the Configuration tab.
3.  Click Security Profile in the Software panel.
4.  In the Services section, click Properties.
5.  Select SSH and click Options.
6.  Change the SSH options.
     a.  To temporarily start or stop the service, click the Start or Stop button.
     b.  To enable SSH permanently, click Start and stop with host. The change takes effect the next time you reboot the host.
7.  Click OK.
For issues related to the vPower NFS Service not starting please review:
KB ID: 1055
Product: Veeam Backup & Replication
Version: All
Published: 2011-07-19
Last Modified: 2020-08-13
Languages: DE | IT | FR | ES

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