The core requirement for implementing a Tableau Server External File Store is to use network-attached storage (NAS). This storage must be configured as a network share that is consistently mounted and accessible with the correct read/write permissions by all nodes within the Tableau Server cluster. This ensures that any node can interact with the centralized data repository, which is essential for the proper functioning of processes like the File Store, Data Engine, and Application Server across the distributed environment. Without this universal accessibility, the cluster would be unable to locate or manage its data, leading to system failure.

A. Configure the file store to be accessible via FTP:

Tableau Server's External File Store feature does not use FTP. It requires a network share using standard protocols like SMB for Windows or NFS for Linux.

B. Enable SSL on the Tableau Server for secure data transfer:

Enabling SSL secures client-to-server and inter-node communication, but it is not the primary mechanism that grants the server access to the network share itself.

D. Increase the virtual memory of the Tableau Server to accommodate the external file store:

Virtual memory (RAM) is a compute resource, while the external file store is a storage solution. Offloading storage to a network share does not necessitate an increase in server memory.

1. Tableau Server Documentation

"Tableau Server External File Store":

Section: Overview: "Tableau Server External File Store enables you to use network attached storage (NAS) for your Tableau Server data storage."

Section: Requirements for External File Store

Subsection: Network Attached Storage: "You must have network attached storage (NAS) that can be mounted as a share on all the Tableau Server nodes... The share must be available using the same mount point on all Tableau Server nodes." This directly supports the correct answer (C) and refutes the others. The documentation specifies NFS for Linux and network shares (SMB) for Windows

which invalidates option A. There is no mention of SSL or virtual memory as prerequisites for share access

invalidating B and D.

Source: Tableau Help. (2023). Tableau Server External File Store. Retrieved from the official Tableau website. The specific URL is subject to change with versions

but the content is found under the Tableau Server administration guides.