Oracle International Corporation

Blaise Sanouillet

Roch Bourbonnais

Eric Carl Taylor

Peter Dunlap

Natalie Ross

Peter Weston Gill

Roch Bourdonnais

Implementations of the present disclosure involve a system and/or method for managing a storage system and, more particularly, for externally managing input/output (I/O) requests to a storage device to avoid large delays in servicing the I/O requests. The management system may maintain I/O request queues for one or more of the storage devices associated with the system. The system may calculate a difference between an order value of the I/O request at the top of the queue and the bottom of the queue for the storage devices. If the calculated difference is above a threshold value, new I/O requests for the storage device are not added to the queue or transmitted to the storage device. In this manner, the management system may force the storage device to service an I/O request that has been stored in the queue for some time without being serviced.

Externally managed I/O starvation avoidance in a computing device

Implementations described and claimed herein provide systems and method for prefetching data. In one implementation, whether a read request for a first data block is part of a sequential access stream is determined. A first trigger for a subsequent data block in the sequential access stream is recorded. A first set of data blocks is prefetched. The first set of data blocks is defined by a first prefetch window associated with the first trigger. A second trigger is recorded for a second subsequent data block in the sequential access stream. A second set of data blocks is prefetched. The second set of data blocks is defined by a second prefetch window associated with the first trigger. A size of the prefetch windows may be dynamically adjusted based on resource contention with the prefetching.

Systems and methods for prefetching data

Implementations claimed and described herein provide systems and methods for the efficient rebuilding of a failed storage device through sequential resilvering. In one implementation, blocks for resilvering are discovered. The blocks correspond to input/output requests not successfully completed for a failed storage device. A coarse grained sorting of the blocks is performed based on a block location of each of the blocks on the failed storage device. The block locations of the blocks are stored in memory according to the coarse grained sorting. A fine grained sorting of the blocks is performed based on the coarse grained sorting of the blocks. The blocks are sequentially resilvered based on the fine grained sorting.

Systems and methods for sequential resilvering

A method for writing a logical data block to storage. The method includes receiving a request to write a logical data block to a storage pool, allocating a number of physical log blocks in a RAID log and a parity block for the logical data block, and writing the logical data block and the parity block to the physical log blocks. The number of the physical log blocks are less than a number of disks storing the RAID log. The method further includes allocating space in a physical slab block in a RAID slab for the logical data block, copying data including the logical data block to the space in the physical slab block, and updating, in the RAID slab, a checksum corresponding to the physical slab block and a parity block that includes the data stripe having the physical slab block based on the data copied.

Growing community of inventors

Rickmansworth, United Kingdom

Blaise Sanouillet