摘要:
A system and method for storing data. In one embodiment, a storage system includes a resource manager and a hierarchical entry tree describing storage entities of the storage system. At each given level of the tree higher than the bottom level, metadata entries summarize storage availability at a level below the given level. The resource manager receives a request to store data of a target size at a target location corresponding to a first portion of the entry tree and scans the entry tree to determine if contiguous, free storage entities of the target size are available at the target location. In response to determining that contiguous, free storage entities of the target size are not available at the target location, the resource manager scans portions of the entry tree outside the first portion to identify contiguous, free storage entities of the target size, where it stores the data.
摘要:
A system and method for storing data. In one embodiment, a file system includes a hierarchy of nodes partitioned into a plurality of containers. The file system further includes metadata associated with each node. First metadata describes each node's references to other nodes and second metadata identifies each node's parent node. The file system further includes a linkage table associated with each container. Each linkage table comprises entries describing links between a node owned by the associated container and other nodes. In response to detecting that a file system error has occurred, the file system identifies a container which corresponds to the detected error, corrects inconsistencies between the first and second metadata associated with each node owned by the container, and corrects inconsistencies between each of the entries of the linkage table associated with the identified container and the first and second metadata.
摘要:
A system and method for storing data. In one embodiment, a file system stores data including associated metadata. In response to detecting that a file system error has occurred, the file system identifies a container including data in which the error occurred and performs a consistency check of the data included in the container. If a bidirectional link exists between the container and another container and if an error is found in the bidirectional link, the file system performs a consistency check of data included in the other container and determines if another bidirectional link exists between the other container and a third container. If another bidirectional link exists between the other container and a third container and if an error is found in the other bidirectional link, the file system performs a consistency check of data included in the third container.
摘要:
A system and method for storing data. In one embodiment, a file system stores data including associated metadata. In response to detecting that a file system error has occurred, the file system identifies a container including data in which the error occurred and performs a consistency check of the data included in the container. If a bidirectional link exists between the container and another container and if an error is found in the bidirectional link, the file system performs a consistency check of data included in the other container and determines if another bidirectional link exists between the other container and a third container. If another bidirectional link exists between the other container and a third container and if an error is found in the other bidirectional link, the file system performs a consistency check of data included in the third container.
摘要:
A system and method for scheduling read and write operations among a plurality of solid-state storage devices. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array comprises an I/O scheduler. The data storage controller is configured to receive requests targeted to the data storage medium, said requests including a first type of operation and a second type of operation. The controller is further configured to schedule requests of the first type for immediate processing by said plurality of storage devices, and queue requests of the second type for later processing by the plurality of storage devices. Operations of the first type may correspond to operations with an expected relatively low latency, and operations of the second type may correspond to operations with an expected relatively high latency.
摘要:
A system and method for effectively scheduling read and write operations among a plurality of solid-state storage devices. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array comprises an I/O scheduler. The characteristics of corresponding storage devices are used to schedule I/O requests to the storage devices in order to maintain relatively consistent response times at predicted times. Should a device exhibit an unscheduled behavior which may be indicative of the device being in an unknown state, the scheduler may schedule one or more reactive operations on the device configured to cause the device to enter a known state.
摘要:
A system and method for effectively scheduling read and write operations among a plurality of solid-state storage devices. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array comprises an I/O scheduler. The data storage controller is configured to receive requests targeted to the data storage medium, said requests including a first type of operation and a second type of operation. The controller is further configured to schedule requests of the first type for immediate processing by said plurality of storage devices, and queue requests of the second type for later processing by the plurality of storage devices. Operations of the first type may correspond to operations with an expected relatively low latency, and operations of the second type may correspond to operations with an expected relatively high latency.
摘要:
A system and method for effectively scheduling read and write operations among a plurality of solid-state storage devices. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array comprises an I/O scheduler. The storage controller is configured to receive a read request targeted to the data storage medium, and identify at least a first storage device of the plurality of storage devices which contains data targeted by the read request. In response to either detecting or predicting the first storage device will exhibit variable performance, the controller is configured to generate a reconstruct read request configured to obtain the data from one or more devices of the plurality of storage devices other than the first storage device.
摘要:
A system and method for effectively scheduling read and write operations among a plurality of solid-state storage devices. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array comprises an I/O scheduler. The characteristics of corresponding storage devices are used to schedule I/O requests to the storage devices in order to maintain relatively consistent response times at predicted times. In order to reduce a likelihood of unscheduled behaviors of the storage devices, the storage controller is configured to schedule proactive operations on the storage devices that will reduce a number of occurrences of unscheduled behaviors.
摘要:
A system and method for effectively scheduling read and write operations among a plurality of solid-state storage devices. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array comprises an I/O scheduler. The characteristics of corresponding storage devices are used to schedule I/O requests to the storage devices in order to maintain relatively consistent response times at predicted times. Should a device exhibit an unscheduled behavior which may be indicative of the device being in an unknown state, the scheduler may schedule one or more reactive operations on the device configured to cause the device to enter a known state.