waiting for each other or in communicating with each other can severely degrade performance. Instead, performant systems require coscheduling of the group. Some flash file systems have several different kinds of internal fragmentation involving "dead space" and "dark space.". See also Defragmentation File system fragmentation Memory management Memory management (operating systems) Block (data storage) Data cluster References Sources http://www.edn.com/design/systems-design/4333346/Handling-memory-fragmentation http://www.sqlservercentral.com/articles/performance+tuning/performancemonitoringbyinternalfragmentationmeasur/2014/ C++ Footprint and Performance Optimization, R. Alexander; G. Bensley, Sams Publisher, First edition, Page no:128, ISBN no:9780672319044 Ibid, Page no:129 File system management Memory management