Conventional computer cluster systems typically use some sort of shared storage for data being used by cluster resources.

Is there no shared storage?

The access to this shared storage is provided by a high bandwitdh switch that allows peaks of 1 Tbit/s.

The shared secondary storage need not to be duplicated and simple unit level redundancy would suffice.

Which kind of negates the purpose of shared storage.

A shared storage may experience data corruption.

Having duplicate instances of services may cause data corruption on the shared storage.

Most importantly, the application must store as much of its state on non-volatile shared storage as possible.

Equally important is the ability to restart on another node at the last state before failure using the saved state from the shared storage.

It is also the name of software from VMware that enables shared storage for virtual machines.