Abstract: A system and method for managing space availability in a distributed striped file system is provided. A master data server is configured to send space availability detection messages to a plurality of data volumes servers hosting constituent volumes of a striped volume set. If one of the constituent volumes in the striped volume set has a low-in-space flag set, then the master data volume instructs all of the constituent volumes to set a low-in-space required flag, and no further writes are accepted for the striped volume set. The low-in-space and low-in-space required flags represent two states, and these states are returned in response to subsequent space availability detection messages from the master data server. A procedure for utilizing reserved space to complete an accepted cross stripe write operation is also provided.

Abstract: An encoding manager facilitates robust single-pass variable bit rate video encoding of a video sequence. Before encoding the video sequence, the encoding manager determines the size of a buffer to use for keeping track of over/under used bits generated during encoding. The encoding manager uses the target bit rate for the video sequence and the length of the video sequence to determine the size of the buffer. After allocating bits to a frame of the sequence, the encoding manager determines the quant to use to encode that frame. The determination of a quant to use to encode a frame is informed by the fullness of the buffer. The encoding manager adjusts the quant to use (and thus the aggressiveness of its encoding) in response to the amount of overflow generated thus far by the encoding of the video sequence.

Abstract: A system and method for enabling write operations to files undergoing write allocation is provided. The system and method generate a shadow state entry of metadata associated with an inode of the file upon receipt of a write operation. During the write allocation process for the inode, the shadow state information is merged with the data stored in the inode to be written to disk.

Abstract: A network storage filer implements a four-phase commit protocol to coordinate consistency points among a group of volumes (a “group consistency point”) such that, upon recovery, all volumes of the group reflect consistency points taken at the same time. The filer records progress at each phase while creating the consistency points of the volumes. Upon recovery, the same or a different filer uses the last recorded progress indicator to ascertain whether the consistency points were completed on all of the volumes in the group. If all the volume consistency points of the group consistency point were completed, the filer users the volume consistency points to mount the volumes. Otherwise, the filer uses an earlier group consistency point to mount the volumes. In either ease, the volumes are consistent with each other.

Abstract: An encoding manager facilitates robust single-pass variable bit rate video encoding of a video sequence. Before encoding the video sequence, the encoding manager determines the size of a buffer to use for keeping track of over/under used bits generated during encoding. The encoding manager uses the target bit rate for the video sequence and the length of the video sequence to determine the size of the buffer. After allocating bits to a frame of the sequence, the encoding manager determines the quant to use to encode that frame. The determination of a quant to use to encode a frame is informed by the fullness of the buffer. The encoding manager adjusts the quant to use (and thus the aggressiveness of its encoding) in response to the amount of overflow generated thus far by the encoding of the video sequence.

Abstract: A system and method for managing file data during consistency points in a file system is provided. A buffer data control structure is modified to include a flags array that tracks various status flags for both a current and a next consistency point (CP). By utilizing multiple pointers within a buffer control structure, the file system may permit write operations to continue to a file undergoing write allocation. Received writes during a write allocation procedure are stored in raw data buffers and the buffer control structure is marked as being dirty for a next CP.

Abstract: A system and method for detecting buffer leaks in a files system utilizing consistency points is provided. Upon receipt of a write operation, a buffer check control structure is written to a raw data buffer. The buffer check control structure comprises a set of magic numbers and a consistency point counter identifying the current CP. At write allocation time, the buffer check control structure is examined to determine that the buffer is being committed to disk during the correct CP.

Abstract: The present invention provides a system and method for flexible space reservations in a file system. An administrator of a storage system selects a fractional reserve percentage, which defines the size of the overwrite reserve that is to be maintained to ensure file writeability.

Abstract: A system and method are provided to manage storage space. The method comprises suspending a request responsive to detecting of a condition indicating a lack of a resource necessary to serve the request; applying a resource management procedure to increase availability of the resource; and, responsive to successful completion of the resource management procedure, serving the request.

Abstract: A system for and method of coordinating actions of components between userspace and kernel are described. The system comprises a processor; zero or more hardware components coupled with the processor; and a memory coupled with the processor and comprising a set of processor-executable instructions. The instructions comprise a component handling state machine responsive to at least one of a kernel component or a userspace component; and at least one component interface thread in communication with the component handling state machine and configured to interact with at least one of the zero of more hardware components responsive to a signal from the component handling state machine.

Abstract: In a write-anywhere filesystem, a write-in-place property allows the write-anywhere filesystem to selectively perform write-in-place processing for write allocation to selected data blocks. The filesystem stores a data block in a storage, and references the data block with both physical and virtual or logical block number references. The block number references allow the filesystem to manage storage of the data blocks through indirection. The data block may be modified, which generates an updated data block in memory having the new data. The filesystem performs write allocation to store the updated data block to the storage. Write-in-place within the write-anywhere filesystem allows the write-anywhere filesystem to write the data block to the same physical location and thus maintain the same physical block number reference while modifying the virtual block number reference.

Abstract: A system and method of controlling redistribution of broadcast content within a personal area network using TSID-DMA mapping to localize devices, wherein some location-aware devices have the capability to derive region identifiers whereas other location agnostic devices localize themselves by adopting the DMA of the first broadcast content received. Rules for redistribution of broadcast content between devices are also established.

Abstract: A system and method for quickly and efficiently determining the number of overwritten blocks between two data containers served by a storage system is provided. A novel vbnspace namespace is provided that is “parallel” to the file system (the “active” file system) and tracks location information (i.e., indirect block pointers) of level 0 data blocks within each data container, e.g., the active file system or a PCPI. The vbnspace namespace effectively eliminates the conventional level 0 data blocks from a storage viewpoint to thereby reduce the quantity of information needed to determine the number of overwritten blocks between the data containers.

Abstract: A method and system mirror flexible volumes in a circular or bi-directional configuration, without creating a deadlock. A source filer maintains a number of log files on a destination filer, where the number of log files is greater than or equal to the number of cache flush operations the primary filer performs between cache flush operations on the destination filer. The source filer can create the log files in advance. Alternatively or in addition, the source filer can create the log files as needed, i.e., the source filer can create a log file when the source filer flushes its cache. Once the destination filer flushes its cache, the log files created prior to the destination filer cache flush can be deallocated or reused.

Abstract: A file system layout apportions an underlying physical volume into one or more virtual volumes (vvols) of a storage system. The underlying physical volume is an aggregate comprising one or more groups of disks, such as RAID groups, of the storage system. The aggregate has its own physical volume block number (pvbn) space and maintains metadata, such as block allocation structures, within that pvbn space. Each vvol has its own virtual volume block number (vvbn) space and maintains metadata, such as block allocation structures, within that vvbn space. Notably, the block allocation structures of a vvol are sized to the vvol, and not to the underlying aggregate, to thereby allow operations that manage data served by the storage system (e.g., snapshot operations) to efficiently work over the vvols. The file system layout extends the file system layout of a conventional write anywhere file layout system implementation, yet maintains performance properties of the conventional implementation.

Abstract: A system and method for managing file data during consistency points in a file system is provided. A buffer data control structure is modified to include a flags array that tracks various status flags for both a current and a next consistency point (CP). By utilizing multiple pointers within a buffer control structure, the file system may permit write operations to continue to a file undergoing write allocation. Received writes during a write allocation procedure are stored in raw data buffers and the buffer control structure is marked as being dirty for a next CP.

Abstract: In one embodiment of the present invention, a method and system are provided to control access to the non-volatile log (NVlog) of a storage server. By controlling access to the NVLog of a storage server the relative disk write bandwidth available to different client write requests can be controlled. The incoming write request can be categorized, and, during times of heavy load, only be permitted to use NVLog space as permitted based on the categorization of each write request. In one embodiment, the present invention includes receiving a write request from a client at a storage server, and determining whether the received write request can be presently logged in a NVlog based on a category of the write request.

Abstract: A memory management system for managing memory of a processing device and a corresponding method thereof are described. The system comprises a memory manager and a garbage collector. The memory manager is configured to allocate memory after dividing discrete units of memory into smaller units. The garbage collector is configured to organize a memory availability collection of free units of memory in the memory manager. The collection is ordered based on at least one of the amount of each of the discrete units available and the allocation age of the discrete units.

Abstract: In a write-anywhere filesystem, a write-in-place property allows the write-anywhere filesystem to selectively perform write-in-place processing for write allocation to selected data blocks. The filesystem stores a data block in a storage, and references the data block with both physical and virtual or logical block number references. The block number references allow the filesystem to manage storage of the data blocks through indirection. The data block may be modified, which generates an updated data block in memory having the new data. The filesystem performs write allocation to store the updated data block to the storage. Write-in-place within the write-anywhere filesystem allows the write-anywhere filesystem to write the data block to the same physical location and thus maintain the same physical block number reference while modifying the virtual block number reference.

Abstract: A method for transferring data of a hybrid virtual volume of a computer data storage system from a source to a destination is disclosed. The method first translates intermingled virtual and physical volume block numbers of the hybrid virtual volume into a data stream having only virtual volume block numbers. The method then sends the data stream to a destination computer.