NetApp ONTAP software is the correct solution for this requirement. ONTAP is a unified data management platform that supports a wide range of storage protocols on the same system. It provides robust support for traditional SAN protocols like iSCSI and Fibre Channel, while also being NetApp's flagship platform for modern SAN modernization with NVMe-over-Fabrics, including NVMe-over-TCP. This allows customers to run existing iSCSI workloads and seamlessly transition or add new, performance-sensitive workloads using NVMe/TCP on the same storage infrastructure, fulfilling the customer's modernization goal.

A. StorageGRID: This is an object storage solution designed for unstructured data using protocols like S3, not a block-based SAN platform.

B. SANtricity OS: This OS powers E-Series/EF-Series arrays. While it supports NVMe over other fabrics (like FC and RoCE), ONTAP is the primary platform for NVMe/TCP.

C. Element software: This is the OS for NetApp SolidFire and HCI systems, which is a scale-out block storage platform primarily focused on the iSCSI protocol.

1. NetApp, Inc. (2023). TR-4982: NVMe/TCP Deployment and Configuration Guide for NetApp ONTAP.

Section: Introduction, Page 5.

Content: "NetApp ONTAP 9.10.1 was the first enterprise storage OS to support the NVMe/TCP protocol... NVMe/TCP can be used in parallel with other SAN protocols such as iSCSI and FC/FCoE on the same ONTAP cluster." This directly confirms ONTAP's capability to handle both iSCSI and the transition to NVMe/TCP.

2. NetApp, Inc. (2023). ONTAP 9 SAN Administration Guide.

Section: Part 1: SAN administration overview, Chapter: SAN protocols supported by ONTAP.

Content: This guide details the configuration and management of multiple SAN protocols within ONTAP, including dedicated chapters for iSCSI, FC/FCoE, and NVMe. This demonstrates that ONTAP is the unified platform for managing these diverse SAN environments.

3. NetApp, Inc. (2023). NetApp ONTAP Datasheet.

Section: Protocol Support.

Content: The official datasheet lists the supported protocols for ONTAP systems (AFF and FAS), explicitly including "iSCSI" and "NVMe/TCP," confirming its suitability for the described scenario.