  We analyze the performance of a state-of-the-art domain decomposition
approach, the Finite Element Tearing and Interconnecting Dual Primal (FETI-DP)
method, for the efficient solution of very large linear systems arising from
elliptic problems discretized by the Virtual Element Method. We provide
numerical experiments on a model linear elliptic problem with highly
heterogeneous diffusion coefficients on arbitrary Voronoi meshes, which we
modify by adding nodes and edges deriving from the intersection with an
unrelated coarse decomposition. The experiments confirm also in this case that
the FETI-DP method is numerically scalable with respect to both the problem
size and number of subdomains, and its performance is robust with respect to
jumps in the diffusion coefficients and shape of the mesh elements.
