Storage Area Networks (SANs) connect storage devices to servers over fast network interconnects. We consider the problem of optimal SAN conﬁguration with the goal of meeting service level agreements (SLAs) for server processes while retaining ﬂexibility for future changes. Our approach proceeds in two stages, by setting up Pseudo-Boolean constraint problems and solving them with an off-the-shelf solver. First, we give an algorithm for assigning storage devices to applications running on the SAN’s hosts. This algorithm tries to balance the workload as evenly as possible over all storage devices. Our second algorithm takes these assignments and computes the interconnections (data paths) that are necessary to achieve the desired conﬁguration while respecting redundancy (safety)requirements in the SLAs. Again, this algorithm tries to balance the workload of all connections and devices in proportion to their capacity. Thus, our network conﬁgurations respect all SLAs and provide ﬂexibility for future changes by avoiding bottlenecks on storage devices or switches.
Towards SLA-Based Optimal Workload Distribution in SANs
Eray Gençay, Carsten Sinz, and Wolfgang Küchlin
In Proc. of the IFIP/IEEE Network Operations and Management Symposium (NOMS 2008), pages 755-758, Salvador, Brazil