IBM TotalStorage Network Attached Storage 200 products are just one part of the overall IBM Storage Networking offering of hardware, software and services. IBM NAS products provide you with one more building block to increase the flexibility, efficiency and effectiveness of your storage networking solutions and deployments. Also, because NAS products are based on an open-system concept, their storage is designed to be as easy to expand in future as the system is to install now, into both heterogeneous and homogeneous network environments.The IBM 5194 NAS Storage Unit Model EXP contains two hot-swap, redundant power supply/fan assemblies. Potential failure-causing conditions are typically reported to the controller using Predictive Failure Analysis (PFA).