This paper describes extensions to the Global Arrays (GA) toolkit to support user-coordinated fault tolerance through checkpoint/restart operations. GA implements a global address space programming model, is compatible with MPI, and offers bindings to multiple popular serial languages. Our approach uses a spare pool of processors to perform reconfiguration after the fault, process virtualization, incremental or full checkpoint scheme and restart capabilities. Experimental evaluation in an application context shows that the overhead introduced by checkpointing is less than 1% of the total execution time. A recovery from a single fault increased the execution time by 8%.