Reconstruct reads in a raid array with dynamic geometries

摘要

A system and method for dynamic RAID geometries. 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 is configured to configure a first subset of the storage devices for use in a first RAID layout, the first RAID layout including a first set of redundant data. The controller further configures a second subset of the storage devices for use in a second RAID layout, the second RAID layout including a second set of redundant data. Additionally, the controller configure an additional device not included in either the first subset or the second subset to store redundant data for both the first RAID layout and the second RAID layout. The controller is further configured to initiate a reconstruct read corresponding to a given read request directed to a particular storage device of the plurality of storage devices, in response to determining the particular storage device is exhibiting a non-error related relatively slow read response.

主权项

1. A computer system comprising:
a data storage subsystem comprising a plurality of storage devices in a redundant array of independent disks (RAID) configuration; and a storage controller configured to:
write a first RAID stripe to the plurality of storage devices including allocating in a particular storage device of the plurality of storage devices, a first amount of intra-device protection data for protecting first RAID data of the first RAID stripe stored on the particular storage device;select a subset of storage devices of the plurality of storage devices for writing a second RAID stripe, wherein the amount of storage devices in the subset is less than the amount of storage devices in the plurality of storage devices, wherein the subset includes the particular storage device; andwrite the second RAID stripe to the subset including allocating in the particular storage device, a second amount of intra-device protection data for protecting second RAID data of the second RAID stripe stored on the particular storage device; wherein the second amount of intra-device protection data is larger than the first amount of intra-device protection data.