Abstract: The present invention relates to methods and systems of snapshot management of a file system in a data storage system. To represent the snapshots, the invention maintains pointers to the root block pointer of each snapshot. When the active file system is modified, this invention avoids overwriting any blocks used by previous snapshots by allocating new blocks for the modified blocks. When the invention needs to put an established block in a new location, it must update a parent block to point to the new location. The update to the parent block may then require allocating a new block for the new parent block and so forth. Parts of the file system not modified since a snapshot remain in place. The amount of space required to represent snapshots scales with the fraction of the file system that users modify. To maintain snapshot integrity, this invention keeps track of the first and last snapshots that use each block in space map blocks spread throughout the file system data space.

Abstract: The invention relates to a multiple QoS file system and methods of processing files at different QoS according to rules. The invention allocates multiple VLUNs at different qualities of service to the multiQoS file system. Using the rules, the file system chooses an initial QoS for a file when created. Thereafter, the file system moves files to different QoS using rules. Users of the file system see a single unified space of files, while administrators place files on storage with the new cost and performance according to attributes of the files. A multiQoS file system enhances the descriptive information for each file to contain the chosen QoS for the file.

Abstract: The present invention relates to methods and systems of snapshot management of a file system in a data storage system. To represent the snapshots, the invention maintains pointers to the root block pointer of each snapshot. When the active file system is modified, this invention avoids overwriting any blocks used by previous snapshots by allocating new blocks for the modified blocks. When the invention needs to put an established block in a new location, it must update a parent block to point to the new location. The update to the parent block may then require allocating a new block for the new parent block and so forth. Parts of the file system not modified since a snapshot remain in place. The amount of space required to represent snapshots scales with the fraction of the file system that users modify. To maintain snapshot integrity, this invention keeps track of the first and last snapshots that use each block in space map blocks spread throughout the file system data space.

Abstract: The present invention relates to methods and systems of snapshot management of a file system in a data storage system. To represent the snapshots, the invention maintains pointers to the root block pointer of each snapshot. When the active file system is modified, this invention avoids overwriting any blocks used by previous snapshots by allocating new blocks for the modified blocks. When the invention needs to put an established block in a new location, it must update a parent block to point to the new location. The update to the parent block may then require allocating a new block for the new parent block and so forth. Parts of the file system not modified since a snapshot remain in place. The amount of space required to represent snapshots scales with the fraction of the file system that users modify. To maintain snapshot integrity, this invention keeps track of the first and last snapshots that use each block in space map blocks spread throughout the file system data space.

Abstract: A desk assembly for mounting to and carrying by a wheelchair or the like in the location of a conventional armrest is disclosed. The desk assembly extends across the lap of the user of the wheelchair in a deployed position, folds to a relatively compact condition, and is pivotally movable to a stored position located where a conventional armrest would be provided. The desk assembly is further formed for selective locking of the desk top in various sloped orientations and movement of the desk top toward or away from the user. A reading lamp is also provided for the desk assembly.

Abstract: A transfer stool for use with and carrying by a wheelchair is disclosed. The transfer stool includes a relatively narrow seat, a plurality of legs foldably secured to the seat for movement to and from a collapsed condition and an extended condition, wheels rotatably mounted to the legs, and a mounting structure for carrying of the transfer stool by the wheelchair in a collapsed condition, preferably in the same location as the conventional armrest structure of the wheelchair. In order to deploy the stool, the user slides the collapsed transfer stool forwardly from its stored position along the side of the chair, rotates the stool to a horizontal position, and extends the legs of the stool. The user can then shift from the chair to the stool, raise the folding back of the stool and move the stool independently of the chair to afford access to areas having relatively narrow passageways that would not accommodate a conventional wheelchair.

Abstract: An energy absorbing motor mount assembly is disclosed in which a mounting element, including an arm having an enlarged head portion, is mounted for reciprocation in fore and aft directions inside a containment housing. Resiliently displaceable energy absorbing means are positioned on either side of the head portion to resist displacement in either the fore or aft direction. The head is dimensioned to prevent removal from the containment housing and is surrounded by a rubber-like member, which resiliently resists displacement in combination with compression springs. The rubber member also resists displacement in directions transversed to the permitted fore and aft displacment. The resilient spring force applied to the head of the mounting element can be adjusted to vary the energy absorption characteristics of the motor mount assembly.