Parity mirroring between controllers in an active-active controller pair
First Claim
1. In a system that includes an array of drives and an active-active controller pair, a method for enhancing performance related to parity, comprising:
- controlling parity-related information being stored in memory of a first controller subsystem and with said parity-related information being associated with a first write operation being conducted using a second controller subsystem; and
conducting at least said first write operation to an array of drives using said second controller subsystem including storing parity on said array of drives, with said parity being different from said parity-related information.
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Accused Products
Abstract
A system and method for efficient parity mirroring between controllers of an active-active controller pair in a redundant array of inexpensive disks (RAID) system is disclosed. When a second controller in an active-active controller pair receives new data to be written to a disk array, it mirrors the new data to a first controller in the active-active controller pair. The second controller then computes new parity for the data stripe associated with the new data. The second controller then opens a parity log and mirrors logical block address (LBA) information for the new data to a first controller in the active-active controller pair. In the event of a failure of the second controller after mirroring the LBA information and prior to completing the write operation, the first controller uses the LBA information to complete the write operation, assuring that the new data and new parity are properly stored on the disk array. If a hard disk in the disk array fails, parity is mirrored between the first and second controllers, rather than just LBA information. If a hard disk and the second controller fail when the first controller contains LBA information, a list containing the LBAs is created and a media error is returned in the event that a host requests in the form of a read operation data contained in the listed LBAs.
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Citations
19 Claims
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1. In a system that includes an array of drives and an active-active controller pair, a method for enhancing performance related to parity, comprising:
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controlling parity-related information being stored in memory of a first controller subsystem and with said parity-related information being associated with a first write operation being conducted using a second controller subsystem; and
conducting at least said first write operation to an array of drives using said second controller subsystem including storing parity on said array of drives, with said parity being different from said parity-related information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19)
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12. A system for enhancing performance related to parity, comprising:
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an array of drives that stores data and parity including at least first parity associated with a first write operation;
a first controller subsystem in communication with said array of drives, said first controller subsystem including a first controller and memory that stores at least first logical block address (LBA)-related information associated with said first write operation; and
a second controller subsystem in communication with said array of drives and including a second controller involved with said first write operation including storing said first parity with said array of drives.
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Specification