QFS
Encyclopedia
QFS is an open source filesystem from Sun Microsystems
. 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
.
SAM extends the QFS file system transparently to archival storage. A SAM-QFS file system may have a relatively small (gigabytes to terabytes) "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
. (QFS also has a single-writer/multi-reader mode which can be used to share disks between hosts without the need for a network connection.)
project in March 2008.
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
. 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
Hierarchical storage management
Hierarchical storage management is a data storage technique which automatically moves data between high-cost and low-cost storage media. HSM systems exist because high-speed storage devices, such as hard disk drive arrays, are more expensive than slower devices, such as optical discs and magnetic...
.
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 (gigabytes to terabytes) "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
Storage area network
A storage area network is a dedicated network that provides access to consolidated, block level data storage. SANs are primarily used to make storage devices, such as disk arrays, tape libraries, and optical jukeboxes, accessible to servers so that the devices appear like locally attached devices...
. (QFS also has a single-writer/multi-reader mode which can be used to share disks between hosts without the need for a network connection.)
History
SAM-QFS, originally developed by LSC Inc, was purchased by Sun in 2001. Sun released the SAM-QFS source code to the OpenSolarisOpenSolaris
OpenSolaris was an open source computer operating system based on Solaris created by Sun Microsystems. It was also the name of the project initiated by Sun to build a developer and user community around the software...
project in March 2008.