Marking impacted similarity groups in garbage collection operations in deduplicated storage systems

Systems and methods for marking similarity groups impacted by a garbage collection operation are disclosed. Similarity groups are used to identify segments associated with objects in a computing system. Using deletion records that identify objects to be deleted, the similarity groups impacted by the deletion records can be identified. The live segments associated with the impacted similarity groups are also identified. This allows segments that are associated with the deleted objects and that are not associated with any live objects to be removed.