Patent application number | Description | Published |
20090222829 | METHOD AND APPARATUS FOR DECOMPOSING I/O TASKS IN A RAID SYSTEM - A data access request to a file system is decomposed into a plurality of lower-level I/O tasks. A logical combination of physical storage components is represented as a hierarchical set of objects. A parent I/O task is generated from a first object in response to the data access request. A child I/O task is generated from a second object to implement a portion of the parent I/O task. The parent I/O task is suspended until the child I/O task completes. The child I/O task is executed in response to an occurrence of an event that a resource required by the child I/O task is available. The parent I/O task is resumed upon an event indicating completion of the child I/O task. Scheduling of any child I/O task is not conditional on execution of the parent I/O task, and a state diagram regulates the child I/O tasks. | 09-03-2009 |
20110191780 | METHOD AND APPARATUS FOR DECOMPOSING I/O TASKS IN A RAID SYSTEM - A data access request to a file system is decomposed into a plurality of lower-level I/O tasks. A logical combination of physical storage components is represented as a hierarchical set of objects. A parent I/O task is generated from a first object in response to the data access request. A child I/O task is generated from a second object to implement a portion of the parent I/O task. The parent I/O task is suspended until the child I/O task completes. The child I/O task is executed in response to an occurrence of an event that a resource required by the child I/O task is available. The parent I/O task is resumed upon an event indicating completion of the child I/O task. Scheduling of any child I/O task is not conditional on execution of the parent I/O task, and a state diagram regulates the child I/O tasks. | 08-04-2011 |
20110196905 | STORING DATA TO MULTI-CHIP LOW-LATENCY RANDOM READ MEMORY DEVICE USING NON-ALIGNED STRIPING - Described herein are method and apparatus for storing data to a low-latency random read memory (LLRRM) device using non-aligned data striping, the LLRRM device being implemented on a storage system. The LLRRM device may comprise a bank comprising a plurality of memory chips, each chip being simultaneously accessible for storing data on a plurality of erase-units (EUs). A storage operating system may maintain, for each chip, a reserve data structure listing reserve EUs and a remapping data structure for tracking remappings between defective EUs to reserve EUs in the chip. A defective EU in a chip may be mapped to a reserve EU from the reserve data structure. Upon receiving a data block to be stored to the LLRRM device at the defective EU, the storage operating system may stripe the received data block across a plurality of chips in a non-aligned manner using the remapped reserve EU. | 08-11-2011 |
20130238832 | DEDUPLICATING HYBRID STORAGE AGGREGATE - Methods and apparatuses for performing deduplication in a hybrid storage aggregate are provided. In one example, a method includes operating a hybrid storage aggregate that includes a plurality of tiers of different types of physical storage media. The method includes identifying a first storage block and a second storage block of the hybrid storage aggregate that contain identical data and identifying caching statuses of the first storage block and the second storage block. The method also includes deduplicating the first storage block and the second storage block based on the caching statuses of the first storage block and the second storage block. | 09-12-2013 |
20130238851 | HYBRID STORAGE AGGREGATE BLOCK TRACKING - Methods and apparatuses for operating a hybrid storage aggregate are provided. In one example, such a method includes operating a first tier of physical storage of the hybrid storage aggregate as a cache for a second tier of physical storage of the hybrid storage aggregate. The first tier of physical storage includes a plurality of assigned blocks. The method also includes updating metadata of the assigned blocks in response to an event associated with at least one of the assigned blocks. The metadata includes block usage information tracking more than two possible usage states per assigned block. The method can further include processing the metadata to determine a caching characteristic of the assigned blocks. | 09-12-2013 |
20130346810 | USE OF APPLICATION-LEVEL CONTEXT INFORMATION TO DETECT CORRUPTED DATA IN A STORAGE SYSTEM - A storage system, such as a file server, receives a request to perform a write operation that affects a data block. In response, the storage system writes to a storage device the data block together with context information which uniquely identifies the write operation with respect to the data block. When the data block is subsequently read from the storage device together with the context information, the context information that was read with the data block is used to determine whether a previous write of the data block was lost. | 12-26-2013 |
20140173198 | METHOD AND APPARATUS FOR DECOMPOSING I/O TASKS IN A RAID SYSTEM - A data access request to a file system is decomposed into a plurality of lower-level I/O tasks. A logical combination of physical storage components is represented as a hierarchical set of objects. A parent I/O task is generated from a first object in response to the data access request. A child I/O task is generated from a second object to implement a portion of the parent I/O task. The parent I/O task is suspended until the child I/O task completes. The child I/O task is executed in response to an occurrence of an event that a resource required by the child I/O task is available. The parent I/O task is resumed upon an event indicating completion of the child I/O task. Scheduling of any child I/O task is not conditional on execution of the parent I/O task, and a state diagram regulates the child I/O tasks. | 06-19-2014 |
20150193168 | CLUSTERED RAID ASSIMILATION MANAGEMENT - In one embodiment, a node is a member of a cluster having a plurality of nodes, where each node is coupled to one or more storage arrays of solid state drives (SSDs) that serve as main storage. The node executed a storage input/output (I/O) stack having a redundant array of independent disks (RAID) layer that organizes the SSDs within the one or more storage arrays as one or more RAID groups. Configuration information is stored as a cluster database. The configuration information identifies (i) one or more RAID groups associated with an extent store, (ii) SSDs within each RAID group, and (iii) an identification of a node that owns the extent store. The cluster database is stored separate and apart from the main storage. | 07-09-2015 |
20150193169 | GLOBAL IN-LINE EXTENT-BASED DEDUPLICATION - In one embodiment, a layered file system of a storage input/output (I/O) stack executes on one or more nodes of a cluster. The layered file system includes a flash-optimized, log-structured layer configured to provide sequential storage of data and metadata (i.e., a log-structured layout) on solid state drives (SSDs) of storage arrays in the cluster to reduce write amplification, while leveraging a data de-duplication feature of the storage I/O stack. An extent store layer of the file system performs and maintains mappings of the extent keys to SSD storage locations, while a volume layer of the file system performs and maintains mappings of the LUN offset ranges to the extent keys. Separation of the mapping functions between the volume and extent store layers enables different volumes with different offset ranges to reference a same extent key (and thus a same extent). | 07-09-2015 |
20150193170 | GLOBAL IN-LINE EXTENT-BASED DEDUPLICATION - In one embodiment, a layered file system includes a volume layer and an extent store layer configured to provide sequential log-structured layout of data and metadata on solid state drives (SSDs) of one or more storage arrays. The data is organized as variable-length extents of one or more logical units (LUNs). The metadata includes volume metadata mappings from offset ranges of a LUN to extent keys and extent metadata mappings of the extent keys to storage locations of the extents on the SSDs. The extent store layer maintaining the extent metadata mappings determines whether an extent is stored on a storage array, and, in response to determination that the extent is stored on the storage array, returns an extent key for the stored extent to the volume layer to enable global inline de-duplication that obviates writing a duplicate copy of the extent on the storage array. | 07-09-2015 |
20150193338 | FLASH OPTIMIZED, LOG-STRUCTURED LAYER OF A FILE SYSTEM - In one embodiment, storage arrays of solid state drives (SSDs) coupled to a node are organized as redundant array of independent disks (RAID) groups. Each storage array includes one or more segments. Each segment has contiguous free space on the SSDs. Data and metadata is organized on the SSDs with a sequential log-structured layout, with the data organized as variable-length extents of one or more logical units (LUNs). Segment cleaning is performed to clean a selected segment by moving the extents of the selected segment that contain valid data to one or more different segments so as to free the selected segment. Additional extents are written as a sequence of contiguous range write operations to the entire free segment with temporal locality to reduce data relocation within the SSDs as a result of the write operations. | 07-09-2015 |