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Problem diagnosis in large distributed computer systems and networks is a challenging task that requires fast and accurate inferences from huge volumes of data. In this paper, the PMC diagnostic model is considered, based on the diagnostic approach of end-to-end probing technology. A probe is a test transaction whose outcome depends on some of the system's components; diagnosis is performed by selecting appropriate probes and analyzing the results. In the PMC model, every computer can execute a probe to test a dedicated system's components. Furthermore, any test result reported by a faulty probe station is unreliable and the test result reported by fault-free probe station is always correct. The aim of the diagnosis is to locate all faulty components in the system based on collection of the test results. A dual-cube DC(n) is an (n + 1)-regular spanning subgraph of a (2n + 1)-dimensional hypercube. It uses n-dimensional hypercubes as building blocks and returns the main desirable properties of the hypercube so that it is suitable as a topology for distributed systems. In this paper, we first show that the diagnosability of DC(n) is n + 1 and then show that adaptive diagnosis is possible using at most 2 2n+1 + n tests for a 2 2n+1 -node distributed system modeled by dual-cubes DC(n) in which at most n + 1 processes are faulty. Furthermore, we propose an adaptive diagnostic algorithm for the DC(n) and show that it diagnoses the DC(n) in three testing rounds and at most 2 2n+1 + O(n 3 ) tests, where each node is scheduled for at most one test in each round. of workstations performing distributed computations. In order to achieve high diagnostic accuracy, a large number of tests may be required, but performing them can be quite expensive. It is therefore essential to improve the cost-efficiency of diagnosis by using only the most relevant measurements of the system.A graph-theoretical model of fault diagnosis, termed the PMC model was proposed in a classic paper by Preparata et al. [19]. In this model, each component in the system is either faulty or fault-free and the fault-status of a component does not change during the diagnosis. The diagnostic approach in this model is based on end-to-end probing technology. A probe is a test transaction whose outcome depends on some of the system's component; diagnosis is performed by selecting appropriate probes and analyzing the results. In the PMC model, every computer can execute a probe to test a dedicated system's components. Furthermore, any test result reported by a faulty probe station is unreliable and any test result reported by fault-free probe station is always correct. The aim of the diagnosis is to locate all faulty components in the system based on collection of the test results.Many researchers in this area have focused on one-step or non-adaptive diagnosis of networks [4,10,16,20,21]. In this type of diagnosis, all test assignments are determined in advance and they can not be rescheduled during the diagnosis process. Nakajima [17] first proposed an adaptive di...

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