HAMMER
System software
HAMMER is a high-availability 64-bit file system developed by Matthew Dillon for DragonFly BSD using B+ trees. Its major features include infinite NFS-exportable snapshots, master–multislave operation, configurable history retention,... Wikipedia
Initial release date: July 2008
Data deduplication: On demand
File system permissions: UNIX permissions
Supported operating systems: DragonFly BSD