Nutanix, Inc.
Managing deduplicated data

Abstract:

Facilitating deduplication of data in a computing system without managing access to reference count variables. A method embodiment commences upon detecting first data unit and calculating a first checksum value. At a later time, a second data unit is received and the system calculates a second checksum value. If the second checksum value is the same as the first checksum value, then the first data unit and the second data unit are the same data and need not be duplicated. In such cases, an entry in the metadata points to the location of the first data unit that is already stored. Additional metadata entries are made in the metadata to associate a Boolean usage state flag and a Boolean deletion state flag with the second checksum value. Periodically scans of the metadata are performed. When both Boolean flags are in a particular state, the deduplicated data is deleted.