Opendedup Develops SDFS, a file-system that does inline deduplication.

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Cross Platform Support - Works on Linux or Windows.
Reduced Storage Utilization - SDFS Deduplication can reduce storage utilization by up to 90%-95%
Scalability - SDFS can dedup a Petabyte or more of data. Over 4TB per gig of memory at 128k chunk size.
Speed - SDFS can perform deduplication/redup at line speed 1 GB/S+
VMWare support - Work with vms - can dedup at 4k block sized. This is required to dedup Virtual Machines effectively
Flexible storage - deduplicated data can be stored locally, on the network across multiple nodes, or in the cloud.
Inline and Batch Mode deduplication - The file system can dedup inline or periodically based on needs. This can be changed on the fly
File and Folder Snapshot support - Support for file or folder level snapshots.