Raid set initialization

摘要

Embodiments of the presently claimed invention enable a RAID set to appear as if it were initialized immediately after a command to initialize a RAID set is initiated. Typically, a driver or other software in the software stack intercepts the command to initialize the RAID set. The driver then responds to user application programs as if the RAID set initialization is complete, even when it is not. After intercepting the RAID set initialization command, the driver will intercept and respond to data read or write commands as if the RAID set were initialized. The driver or other software will then, typically initialize the RAID set using background tasks. In certain instances, data stored in a non-RAID configuration may be migrated to a RAID configuration during the initialization process.

主权项

1. A method for initializing a redundant array of inexpensive disks (RAID) set, the method comprising:
creating information by a processor executing instructions according to a driver software module, the information describing an initialization state of the RAID set corresponding to an intercepted RAID set initialization command, wherein the driver software module is located below a RAID set configuration application program associated with an application layer in a layered software stack, and the driver software module allocates an initial stripe of the RAID set for storing the information describing the initialization state of the RAID set; performing by the driver software module:
intercepting a data transfer command associated with the RAID set, wherein the data transfer command is from an initiator; andwhen the intercepted data transfer command is a read command addressing an uninitialized portion of the RAID set, transmitting data to the initiator of the data transfer command; andwhen the transfer command is a write command to the initial stripe of the RAID set, performing:
reallocating the information describing the initialization state of the RAID set to a second stripe of the RAID set; andwriting data associated with the write command to the initial stripe of the RAID set; andfurther updating the information describing the initialization state of the RAID set in the second stripe of the RAID set when required.