"A datastore with the same name and backing configuration already exists in the current datacenter. Change the datastore name and backing configuration to continue."
While adding NFS datastore on esxi server I saw above error. This NFS drive was already added on the Esxi001 successfully, but when tried to add to another Esxi002 using add datastore wizard I was keep getting error and not allowed to add it. Just for your information when you add VMFS datastore, it is by default added and mounted to all other configured esxi servers. But for NFS datastore you need to mount it on each esxi host separately.
Check earlier article to view VMWare ESXi add and create NFS datastore.
For resolution you have to mount NFS datastore once to any of one ESXi server in the cluster, once it is added, go the datastores view, from the list select NFS datastore, Right click on it, Click Mount Datastore to Additional Hosts. In the wizard, it shows the list of esxi host where this datastore is not mounted. Click on the host to mount and click OK.
To confirm NFS is mounted correctly, you can browse datastores in esxi host or in the datastores tab view, check the Hosts tab.
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