Dynamic resource allocation for serial attached SCSI devices

摘要

Various embodiments of the invention provide resource management of available data bandwidth of a SAS system in a non-uniform way. In certain embodiments, arbitration wait time values are adaptively modified to achieve a specified performance quota for a link.

主权项

1. A resource allocation controller operable in a storage network, the controller comprising:
a performance measurement element that measures a performance metric on a storage expander within the storage network; a comparator coupled to the performance measurement element, the comparator compares the measured performance metric to a threshold value and generates a comparison result; an arbitration wait time (“AWT”) adjustment circuit coupled to the AWT adjustment circuit is configured to dynamically increase and decrease an AWT value based on the comparison result; and a demand frequency monitoring circuit to detect a demand frequency of an address, wherein the controller sets the threshold value higher in response to detecting an increase in the demand frequency and lower in response to detecting a reduction in the demand frequency.