Methods and apparatus for shared storage journaling
First Claim
1. A method for use in a shared storage system, the method comprising:
- detecting a change to file system metadata stored in a first computer of multiple computers having access to the shared storage system;
creating a journal, the journal identifying executed operational steps used to change the file system metadata stored in the first computer;
storing the journal to the shared storage system, storage of the journal enabling a second computer to subsequently retrieve and execute at least portions of the journal to carry out the executed operational steps to modify the file system metadata of the shared storage system in accordance with a failed attempt by the first computer to change a copy of the file system metadata in the shared storage system;
maintaining access right schedule information, the access right schedule information identifying which of the multiple computers had access to different regions of the shared storage at different times; and
storing at least a portion of the access right schedule information to the journal.
10 Assignments
0 Petitions
Accused Products
Abstract
Multiple computers have access to a shared storage system. The computers negotiate with each other for access rights (e.g., READ or WRITE) to regions of the storage system. After negotiating for permission to modify a location (e.g., a range of addresses) of the shared storage system, a given computer copies data from the shared storage system into its own corresponding cache. The given computer granted the permission then modifies the data in its cache while maintaining a separate journal of corresponding changes to metadata. The given computer writes the journal to a dedicated region of the storage system. Thereafter, the given computer attempts to flush contents of the modified cache to the storage system. If the given computer crashes while attempting to flush the modified cache to the shared storage system, a healthy one of the multiple computers utilizes the journal information in the storage system to recover metadata.
-
Citations
23 Claims
-
1. A method for use in a shared storage system, the method comprising:
-
detecting a change to file system metadata stored in a first computer of multiple computers having access to the shared storage system; creating a journal, the journal identifying executed operational steps used to change the file system metadata stored in the first computer; storing the journal to the shared storage system, storage of the journal enabling a second computer to subsequently retrieve and execute at least portions of the journal to carry out the executed operational steps to modify the file system metadata of the shared storage system in accordance with a failed attempt by the first computer to change a copy of the file system metadata in the shared storage system; maintaining access right schedule information, the access right schedule information identifying which of the multiple computers had access to different regions of the shared storage at different times; and storing at least a portion of the access right schedule information to the journal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 23)
-
-
11. A computer system for reducing data corruption in a shared storage system, the computer system comprising:
-
a processor; a memory unit that stores instructions associated with an application executed by the processor; a communication interface that supports communication with other nodes of the storage area network; and an interconnect coupling the processor, the memory unit, and the communication interface, enabling the computer system to execute the application and perform operations of; detecting a change to file system metadata initiated by a first computer of multiple computers having access to the shared storage system; creating a journal, the journal identifying operational steps associated with the change to the file system metadata; storing the journal to the shared storage system, storage of the journal enabling a second computer to subsequently retrieve and execute at least portions of the journal to carry out the executed operational steps to modify the file system metadata of the shared storage system in accordance with a failed attempt by the first computer to change a copy of the file system metadata in the shared storage system; maintaining access right schedule information, the access right schedule information identifying which of the multiple computers had access to different regions of the shared storage at different times; and storing at least a portion of the access right schedule information to the journal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
21. A computer program product including a computer-storage medium having instructions stored thereon for processing data information, such that the instructions, when carried out by a processing device, enable the processing device to perform the steps of:
-
detecting a change to file system metadata stored in a first computer of multiple computers having access to a shared storage system; creating a journal, the journal identifying operational steps associated with the change to the file system metadata; storing the journal to the shared storage system, storage of the journal enabling a second computer to subsequently retrieve and execute at least portions of the journal to carry out the executed operational steps to modify the file system metadata of the shared storage system in accordance with a failed attempt by the first computer to change a copy of the file system metadata in the shared storage system; maintaining access right schedule information, the access right schedule information identifying which of the multiple computers had access to different regions of the shared storage at different times; and storing at least a portion of the access right schedule information to the journal.
-
-
22. A computer system having access to a shared storage system, the computer system including a processor coupled to a memory, and the computer system including:
-
means for detecting a change to file system metadata stored in a first computer of multiple computers having access to the shared storage system; means for creating a journal, the journal identifying operational steps associated with the change to the file system metadata; and means for storing the journal to the shared storage system, storage of the journal enabling a second computer to subsequently retrieve and execute at least portions of the journal to carry out the executed operational steps to modify the file system metadata of the shared storage system in accordance with a failed attempt by the first computer to change a copy of the file system metadata in the shared storage system; means for maintaining access right schedule information, the access right schedule information identifying which of the multiple computers had access to different regions of the shared storage at different times; and means for storing at least a portion of the access right schedule information to the journal.
-
Specification