Some theorems to aid in solving the file allocation problem
Enrique Grapa, Geneva G. Belford · Communications of the ACM · 1977
The file allocation problem — i.e. the problem of finding the optimal set of network sites at which to locate copies of a file — is known to be, in general, polynomial complete. Heuristics and other aids to finding optimal, or near-optimal, solutions are therefore much needed. In this paper we present three theorems which can be applied a priori to indicate that certain sites should (or should not) be included in an optimal allocation.