VMware NSX-T Data Center
VMware NSX 4.1.x
NSX SFTP backups are not configurable on standby Global Managers by design because the process to revert Global Managers from backup leverages the SFTP backups taken from the Active Global Managers.
This warning banner is not present in the standby Global Manager UI starting in VMware NSX 4.2.
For VMware NSX versions prior to 4.2, this warning banner can be safely disregarded when seen in the standby Global Manager UI.
Link to Release Notes for NSX 4.2 that includes the following note regarding this warning banner;
Fixed Issue 3347964: Unwanted banner message is showing on NSX UI related to backup configuration only on stand-by GM instance.
No functional impact, user will be seeing a banner message related to backup but backup is not applicable on standby GM instance.
For reference, link to Backing Up and Restoring NSX Manager or Global Manager on NSX-T Data Center 3.2
For further information see Troubleshooting NSX Backup and Restore Failures.