This paper describes a mechanism for secondary storage garbage collection that may be used to reclaim inaccessible resources in decentralized persistent object based systems. Schemes for object addressing and object identification are discussed and a proposal is made which handles volatile objects separately from persistent objects. The garbage collection of the space of volatile objects is decoupled from the garbage collection of the space of persistent objects. The first kind of garbage collection can avoid the complexity and overhead of a distributed algorithm by classifying "exported" objects as persistent. The problem of detecting and collecting ''distributed garbage" is then deferred to garbage collection of persistent objects.