Static load balancing for file systems in a multipath I/O environment

摘要

A data processing system includes a file server and a storage controller linking the file server to a storage array. There are alternative data paths between the file server and the storage controller for accessing logical units of storage (LUNs) in the storage array. A file system is striped across the LUNs. For load balancing, the file server is programmed with a facility for selecting mappings between the LUNs and the data paths. Upon mounting the file system, the facility is invoked to get a next mapping between the LUNs and the data paths, and this next mapping is used during read and write access to the mounted file system. The facility can also be invoked to get another mapping when another file system is mounted on the LUNs.

主权项

1. A computer-implemented method of load balancing over data paths between a file server and a storage controller of a storage system, the storage system including a storage array storing logical units of storage, the storage controller providing the file server with access to the logical units of the storage in the storage array, and a file system is striped across a sequence of a certain number of the logical units of the storage so that sequential read or write access to a file in the file system sequentially accesses the certain number of logical units of storage for concurrent transfer of read or write data between the file server and the storage controller over more than one of the data paths between the file server and the storage controller, the method comprising a data processor of the file server executing computer instructions stored on a non-transitory computer-readable storage medium to perform the steps of:
(a) programming the data processor with a facility for providing mappings between the certain number of logical units of the storage and the data paths between the file server and the storage controller for read or write access to the certain number of logical units of the storage; (b) upon mounting the file system to enable read-write access to the file system, invoking the facility to obtain a next mapping between the certain number of logical units of the storage and the data paths between the file server and the storage controller for read or write access to the certain number of logical units of the storage, and then (c) upon read or write access of the file server to the data storage of a file in the mounted file system, using the next one of the mappings between the certain number of logical units of the storage and the data paths between the file server and the storage controller to select and use one of the data paths for conveying data read from or written to the file in the mounted file system.