NSX-T - Error to fetch SSH Fingerprint

Issue
Recently I needed to set up backups of a NSX-T Manager for a one time backup. I have performed the procedures shown in this link: I logged in with admin privileges to an NSX Manager at https://<nsx-manager-ip-address>. Selected System > Backup & Restore then Edit (in the upper right of the page to configure backups) and filled up all forms except the once regarding the SSH fingerprint of the server that stores the backups, because as indicated, I could leave it blank.
Doing so, I received the following error message:

Error while fetching fingerprint of fileserver Algorithm negotiation fail. Possibly, there is no ecdsa and ed25519 support for public keys (Error code: 29259)
- Please retry or provide the fingerprint.

By carefully reading the documentation about the Prerequisites, at the link says:

Verify that you have the SSH fingerprint of the backup file server. Only an SHA256 hashed ECDSA key is accepted as a fingerprint. See Find the SSH Fingerprint of a Remote Server.

Solution
In case was not practicable to follow the instructions suggested in the link, is it possible to get the SSH Fingerprint of a Remote Server through a REST API request. Info about NSX-T Data Center API Guide regarding NSX-T Data Center 2.5.0 can be found here.

So, to fetch the SHA256 fingerprint of the SFTP backup target, in my case, I used the following CURL command:

curl --user admin -H 'Content-Type: application/json' --request POST  https://<nsx-manager-ip-address>/api/v1/cluster/backups?action=retrieve_ssh_fingerprint -k -d '{ "server":"<Target-Backup-IP-Address>","port":22}'

The NSX-T Manager API responds with the SHA256 fingerprint of the SFTP server:

A very great post on configuring and troubleshooting NSX-T SFTP backups, wrote by Gary Hills is available here.

That's it.

VEEAM - Configure a NAS backup Job

New capabilities that redefine NAS data protection to deal with the world of massive file data, have been released with the new veeam v10 version.
Below I will covering step by step how to setup and configure on Veeam 10 to backup file from a NAS file share.
First of all let's see the official documentation available here, to understand which components must be present or added to the backup infrastructure and to understand "How File Share Backup Works".

Before to begin to adding an SMB file share to the inventory of the virtual infrastructure is possible to check prerequisites, limitations and the official procedures here.

To add an SMB file share, once opened Veeam Backup and Replication console proceed as follows:

• Open the Inventory view.
  
  Click on File Shares and then ADD FILE SHARE.
  
  
  
  
  
  
• Click SMB share (in my case I have a NAS that run a CIFS service)
  
  
  
  
  
  
• In the Shared folder field, specify the path to an SMB file share in the \\server\folder format.
  
  Select the This share requires access credentials check box and provide proper credentials to get full access control to shared folder.
  
  
  
  
  
  
• Clicking on Advanced the window shows several options.
  
  Leave the enabled the default option "Backup directly from the file share" clicking on OK and then click Next >.
  
  
  
  
  
  
• Click Choose... next to the File proxy field to select a file proxy.
  
  From the Cache repository drop-down list, select a cache repository where temporary cache files must be stored.
  
  Use the Backup I/O control slider to define how fast all proxies can read data from the source file share.
  
  Click Apply to save the configured settings.
  
  
  
  
  
  
• Wait while required components are installed and configured, then click Next>.
  
  
  
  
  
  
• At the Summary step, reviewed the configuration, click Finish to finalize the setup and exit the wizard.
  
  
  
  
  
  

In the following steps we will see how to set up a backup job of the NAS file share content.

• Open the Inventory view.
  
  Right click on SMB file share select Add to backup job and then click on New job...
  
  
  
  
  
  
• In the Name field, specify the name of the backup job and click Next >.
  
  
  
  
  
  
• Select File or folder and click Add...
  
  
  
  
  
  
• Explore Folders, select which ones you prefer and click OK.
  
  
  
  
  
  
• In Advanced is possible to create extension masks to Include or Exclude files.
  
  
  
  
  
  
• Select the desired Backup repository.
  
  Use the Keep all file versions for the last field to define short-term retention policy: specify how long copies of all recent file versions must be kept in the short-term backup repository.
  
  Click Next >.
  
  
  
  
  
  
• Add a Secondary Target otherwise click Next >.
  
  
  
  
  
  
• Schedule the job to run automatically.
  
  
  
  
  
  
• Review details and click Finish.
  
  
  
  
  
  
• The job run as expected.
  
  
  
  
  
  
  

That's it.

Further info: v10: Seriously Powerful NAS Backup at Scale