Exactly that. We have 2000+ users, and 1000+ compute nodes. Each compute node does have a certain amount of local SSD (`$L_SCRATCH`) for job-local storage, but for everything else we have to use some sort of network-accessed file system. For us, that is NFSv4 for longer-lasting data (`$HOME` and `$GROUP_HOME`) to the Isilon over Ethernet, and short-term data (`$SCRATCH` and `$GROUP_SCRATCH`) to Lustre over Infiniband.

(Yes, Infiniband! Hello, Mellanox!)