Host discovery and handling of ALUA preferences and state transitions

摘要

Various systems and methods can discover asymmetric logical unit (LUN) access (ALUA) preferences and/or state transitions and use those preferences and/or state transitions to control how a host accesses a LUN in an ALUA array. One such method involves detecting a preferred controller for a LUN and then detecting that a current owner controller of the LUN is not the preferred controller. In response, the method can initiate an ownership change from the current owner controller to the preferred controller. Another method involves detecting an initial state of a first controller with respect to a LUN. The method then detects a subsequent state of the first controller with respect to the LUN subsequent to detecting the initial state. The method can then cause a computing device to access the LUN via a second controller, in response to the subsequent state not being the active optimized state.

主权项

1. A method comprising:
detecting a preferred controller for a logical unit (LUN) within an asymmetric LUN access (ALUA) array, wherein
a multipathing agent is unable to obtain information identifying the preferred controller from the ALUA array, andthe detecting the preferred controller is based on an initial configuration of the ALUA array; detecting that a current owner controller of the LUN is not the preferred controller; and initiating an ownership change from the current owner controller to the preferred controller, wherein
designation of the preferred controller as preferred is unaffected by the ownership change, andthe detecting the preferred controller, the detecting the current owner controller, and the initiating are performed by a computing device implementing the multipathing agent.