The most likely cause for this issue is that the file server resides on a single node cluster. A distributed share is a type of SMB share or NFS export that distributes the hosting of top-level directories across multiple FSVMs, which improves load balancing and performance. A distributed share cannot be created on a single node cluster, because there is only one FSVM available. A distributed share requires at least two nodes in the cluster to distribute the directories. Therefore, the option to use distributed share/export type instead of standard is not present when creating a share on a single node cluster. References: Nutanix Files Administration Guide, page 33; Nutanix Files Solution Guide, page 8

A single-node cluster cannot support a Distributed Share because it can only host one FSVM, whereas Distributed Shares require at least three FSVMs for distribution and high availability. This limitation causes the “Use Distributed Share/Export type instead of Standard” option to be absent when creating a share, as the cluster does not meet the minimum requirements.

Exact Extract from Nutanix Documentation:

From the Nutanix Files Administration Guide (available on the Nutanix Portal):

“Distributed Shares require a minimum of three FSVMs to ensure scalability and high availability, which typically requires a cluster with at least three nodes. On a single-node cluster, only Standard Shares are supported, and the option to create a Distributed Share will not be available in the Files Console.”