QFS
QFS is a filesystem from Oracle. It is tightly integrated with SAM, the Storage and Archive Manager, and hence is often referred to as SAM-QFS. SAM provides the functionality of a hierarchical storage manager.
Features
QFS supports some volume management capabilities, allowing many disks to be grouped together into a file system. File system metadata can be kept on a separate set of disks, which is useful for streaming applications where long disk seeks cannot be tolerated.SAM extends the QFS file system transparently to archival storage. A SAM-QFS file system may have a relatively small "disk cache" backed by petabytes of tape or other bulk storage. Files are copied to archival storage in the background, and transparently retrieved to disk when accessed. SAM-QFS supports up to four archival copies, each of which can be on disk, tape, optical media, or may be stored at a remote site also running SAM-QFS.
Shared QFS adds a multi-writer global filesystem, allowing multiple machines to read from & write to the same disks concurrently through the use of multi-ported disks or a storage area network.