Fibre Channel Storage Array Methods for Handling Cache-Consistency Among Controllers of an Array and Consistency Among Arrays of a Pool

摘要

Storage arrays, systems and methods for operating storage arrays for maintaining consistency in configuration data between processes running on an active controller and a standby controller of the storage array are provided. One example method includes executing a primary process in user space of the active controller. The primary process is configured to process request commands from one or more initiators, and the primary process has access to a volume manager for serving data input/output (I/O) requests and non-I/O requests. The primary process has primary access to the configuration data and includes a first logical unit (LU) cache for storing the configuration data. The method also includes executing a secondary process in user space of the standby controller. The secondary process is configured to process request commands from one or more of the initiators, wherein the secondary process does not have access to the volume manger. The secondary process has a second LU cache for storing the configuration data, and the second LU cache is used by the secondary process for responding to non-I/O requests. The method includes receiving, at the primary process, an update to the configuration data and sending, by the primary process, the update to the configuration data to the secondary process for updating the second LU cache. When the primary process receives an acknowledgement from the secondary process that the update to the configuration data was received, then the updates to the configuration data are committed to the first LU cache of the active controller.