Load balancing logical units in an active/passive storage system
An approach is provided in which a storage system includes a first storage controller, a second storage controller, and multiple logical units. The storage system determines that a controller traffic load ratio between the first storage controller and the second storage controller has reached a threshold. In turn, the storage system selects one of the logical units and changes a preferred controller ownership of the selected logical unit from the first storage controller to the second storage controller to balance the controller traffic load ratio.
1. An information handling system comprising:
one or more processors;
a memory coupled to at least one of the processors;
a plurality of storage controllers;
a plurality of logical units; and
a set of computer program instructions stored in the memory and executed by at least one of the processors in order to perform actions of:
determining that a controller traffic load ratio between a first storage controller and a second storage controller has reached a threshold, wherein the first storage controller and the second storage controller are included in the plurality of storage controllers and correspond to at least one of the plurality of logical units;
changing, by the storage system, a preferred controller ownership corresponding to a selected one of the plurality of logical units from the first storage controller to the second storage controller in response to the determination;
sending an error message to a host system upon receiving a request to the first storage controller to send or retrieve data to or from the selected logical unit, wherein the error message indicates that the first storage controller is not the current controller of the selected logical unit;
receiving a second request to the second storage controller to send or retrieve data to or from the selected logical unit; and
sending a valid response to the host system indicating that the host system may send and receive data to the selected logical unit through the second controller.
2. The information handling system of claim 1 wherein the information handling system configures the first storage controller and the second storage controller in an active/passive controller configuration.
3. The information handling system of claim 1 wherein, prior to the determination that the controller traffic load ratio has reached the threshold, the set of instructions, when executed by at least one of the processors, performs further actions of:
identifying a first data traffic amount passing through the first storage controller corresponding to one or more first logical units included in the plurality of logical units;
identifying a second data traffic amount passing through the second storage controller corresponding to one or more second logical units included in the plurality of logical units; and
computing the controller traffic load ratio based upon the first data traffic amount and the second data traffic amount.
4. The information handling system of claim 1 wherein the set of instructions, when executed by at least one of the processors, performs further actions of:
displaying an ownership configuration window to a user;
receiving an ownership configuration selection from the user;
determining that the ownership configuration selection is a dynamic ownership selection; and
configuring the information handling system to balance the controller traffic load ratio, wherein the balancing includes changing one or more preferred controller ownerships of one or more of the plurality of logical units when the controller traffic load ratio reaches the threshold.
5. The information handling system of claim 4 wherein the threshold is an auto-balance threshold received from the user.
6. The information handling system of claim 1 wherein each of the plurality of logical units corresponds to at least a portion of a physical storage device.
7. A computer program product stored in a non-transitory computer readable storage medium, comprising computer program code that, when executed by an information handling system, causes the information handling system to perform actions comprising:
determining that a controller traffic load ratio between a first storage controller and a second storage controller has reached a threshold, wherein the first storage controller and the second storage controller are included in the plurality of storage controllers and correspond to at least one of the plurality of logical units;
changing, by the storage system, a preferred controller ownership corresponding to a selected one of the plurality of logical units from the first storage controller to the second storage controller in response to the determination;
sending an error message to a host system upon receiving a request to the first storage controller to send or retrieve data to or from the selected logical unit, wherein the error message indicates that the first storage controller is not the current controller of the selected logical unit;
receiving a second request to the second storage controller to send or retrieve data to or from the selected logical unit; and
sending a valid response to the host system indicating that the host system may send and receive data to the selected logical unit through the second controller.
8. The computer program product of claim 7 wherein the computer program code that, when executed by the information handling system, causes the information handling system to configure the first storage controller and the second storage controller in an active/passive controller configuration.
9. The computer program product of claim 7 wherein the computer program code that, when executed by the information handling system, causes the information handling system to perform further actions of:
identifying a first data traffic amount passing through the first storage controller corresponding to one or more first logical units included in the plurality of logical units and;
identifying a second data traffic amount passing through the second storage controller corresponding to one or more second logical units included in the plurality of logical units; and
computing the controller traffic load ratio based upon the first data traffic amount and the second data traffic amount.
10. The computer program product of claim 7 wherein the computer program code that, when executed by the information handling system, causes the information handling system to perform further actions of:
displaying an ownership configuration window to a user;
receiving an ownership configuration selection from the user;
determining that the ownership configuration selection is a dynamic ownership selection; and
configuring the information handling system to balance the controller traffic load ratio, wherein the balancing includes changing one or more preferred controller ownerships of one or more of the plurality of logical units when the controller traffic load ratio reaches the threshold.
11. The computer program product of claim 10 wherein the threshold is an auto-balance threshold received from the user.