Opendedup is a project that develops a deduplication based filesystem for Windows and Linux called SDFS. SDFS is designed to support the unique needs of virtual environments and supports enhanced functionality for VMWare, Xen, and KVM. It can deduplicate a petabyte or more of data. It supports over 3TB per gigabyte of memory at a 128k chunk size. It can perform deduplication/reduplication at a line speed of 250 MB/s or more. VMware support: it works with vms, and can deduplicate at 4k block sizes. This is required to deduplicate Virtual Machines effectively Deduplicated data can be stored locally, on the network across multiple nodes, or in the cloud. The filesystem can deduplicate inline or periodically based on needs. This can be changed on the fly. There is support for file or folder level snapshots.