Use of read data tracking and caching to recover from data corruption
AssigneeVeritas Operating Corporation
InventorsOleg Kiselev, Ronald S. Karr
Life of this patent
Estimating the term…
Abstract
In a system in which read data tracking and caching is used to recover from data corruption, a first request to read data from a primary data mirror is received from a computer system. Data is read from the primary data mirror in response to receiving the first request. Additionally data from a mirrored copy of the primary data mirror is read. Data read from the primary data mirror is returned to the computer system. Data read from the mirrored copy is stored into a memory device. If a second request is received from the computer system to read the same data of the first request, data stored in the memory device may be returned in response thereto.
Claims19
A method comprising:
- reading data from a first memory configured to store a data volume in response to receiving a first request to read data from the data volume, wherein the first request is received from a computer system;
- reading data from a second memory configured to store a mirrored copy of the data volume in response to receiving the first request;
- comparing the data read from the first memory with the data read from the second memory;
- returning the data read from the first memory to the computer system, wherein the data read from the first memory is returned regardless of whether the data read from the first memory compares equally to the data read from the second memory;
- storing the data read from the second memory into a memory device.
A computer readable medium comprising instructions executable by a first computer system, wherein the first computer system performs a method in response to executing the instructions, the method comprising:
- reading data from a first memory configured to store a data volume in response to receiving a first request to read data from the data volume, wherein the first request is received from a second computer system;
- reading data from a second memory configured to store a mirrored copy of the data volume in response to receiving the first request;
- comparing the data read from the first memory with the data read from the second memory;
- returning the data read from the first memory to the second computer system, wherein the data read from the first memory is returned regardless of whether the data read from the first memory compares equally to the data read from the second memory;
- storing the data read from the second memory into a memory device.
A data processing system comprising;
- a first memory for storing a data volume;
- a second memory for storing a mirrored copy of the data volume;
- a first computer system coupled to the first and second memories, wherein the first computer system comprises a computer readable medium that stores instructions executable by the first computer system, wherein the first computer system performs a method in response to executing the instructions, the method comprising:
- reading data from the first memory in response to receiving a first request to read data from the data volume, wherein the first request is received from a second computer system in data communication with the first computer system;
- reading data from the second memory in response to receiving the first request;
- comparing the data read from the first memory with the data read from the second memory
- returning the data read from the first memory to the second computer system, wherein the data read from the first memory is returned regardless of whether the data read from the first memory compares equally to the data read from the second memory;
- storing the data read from the second memory into a memory device of the first computer system.
A data processing system comprising;
- means for receiving a first request to read data from a data volume, wherein the first request is received from a computer system;
- means for reading data from a first memory for storing the data volume in response to receiving the first request;
- means for reading data from a second memory for storing a mirrored copy of the data volume in response to receiving the first request;
- means for returning the data read from the first memory to the computer system, regardless of whether the data read from the first memory compares equally to the data read from the second memory;
- means for storing the data read from the second memory into a memory device;
- means for comparing the data from the first memory with the data from the second memory.
Dependencies are inferred from the claim text.