US 8,554,997 B1Granted

Method and system for mirrored multi-dimensional raid

AssigneeDSSD, Inc.

InventorsJeffrey S. Bonwick, Michael W. Shapiro

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method for storing data. The method includes receiving a request to write data, determining that the storage mode for the data is mirrored mode, selecting a Redundant Array of Independent Devices (RAID) grid location in a RAID grid to write the data based on the storage mode, writing the data to memory, updating a data structure to indicate that the RAID grid location is filled, and determining a data grid is filled. Based on the determination, determining a first physical address and a second physical address in persistent storage corresponding to the RAID grid location; writing the data to a first physical location in the persistent storage corresponding to the first physical address and writing the data to a second physical location in the persistent storage corresponding to the second physical address, and writing the parity values associated with data grid to the persistent storage.

Claims19

Dependent claims

A non-transitory computer readable medium comprising instructions, which when executed by a processor perform a method, the method for storing data comprising:

receiving a request to write data;
determining a storage mode for the data, wherein the storage mode for the data is mirrored mode;
selecting a Redundant Array of Independent Devices (RAID) grid location in a RAID grid to write the data based on the storage mode;
writing the data to memory, wherein the data is temporarily stored in the memory;
updating a data structure to indicate that the RAID grid location is filled;
determining, using the data structure, whether a data grid in the RAID grid is filled, wherein the RAID grid location is in the data grid;
based on a determination that the data grid is filled:
calculating parity values for the RAID grid using the data;
determining a first physical address in persistent storage corresponding to the RAID grid location;
determining a second physical address in the persistent storage corresponding to the RAID grid location;
writing the data to a first physical location in the persistent storage corresponding to the first physical address;
writing the data to a second physical location in the persistent storage corresponding to the second physical address;
and
writing the parity values associated with data grid to the persistent storage.

11 more elements

A non-transitory computer readable medium comprising instructions, which when executed by a processor perform a method, the method for obtaining reconstructing data, comprising:

receiving a first request for data;
identifying a grid location in a Redundant Array of Independent Devices (RAID) grid associated with the data, wherein the grid location is associated with a first physical location and a second physical location;
making a first determination that a storage mode for the grid location is mirrored mode;
based on the first determination, making a second determination that the first physical location is busy;
based on the second determination, issuing a second request for the data to the second physical location;
and
in response to the second request, receiving the data from the second physical location,
wherein the grid location is associated with a virtual stripe,
wherein the virtual stripe is associated with a first physical stripe and a second physical stripe,
wherein the first physical location is part of the first physical stripe and the second physical location is part of the second physical stripe.

7 more elements

Dependencies are inferred from the claim text.