When building or expanding an HPC cluster, one of the biggest architectural decisions is storage design. Many small and mid-sized clusters start with NFS because it is simple, reliable, and easy to manage. But as workloads grow, storage often becomes the hidden bottleneck. So the real question is: When is NFS enough, and when does an HPC cluster actually require a parallel file system like Lustre, BeeGFS, or GPFS? This article breaks down the practical factors that help HPC admins make that decision. ⸻ Understanding the Difference NFS (Network File System) NFS is a centralized file-sharing system where compute nodes access data from a single storage server.…