Patent attributes
Storage divisions are selected for garbage collection by use of a first selection criterion that is based on an amount of storage capacity freed by reclaiming the respective storage divisions. The first selection criterion may be overridden by a second, different selection criterion in response to determining that a wear variance of the storage divisions exceeds a threshold. The second selection criterion may select a storage division to reclaim based on a wear-level of the storage division. Overrides of the first selection criterion may be limited to a particular override frequency and/or period. The first selection criterion may comprise a logarithmic comparison of the amount of invalid data within the storage divisions. The amount of invalid data in a storage division may be calculated in terms of recovery blocks, having a size that exceeds the size of the physical storage locations within the storage divisions.