Quality of Service in Virtual Computing Environments
Methods and apparatus facilitate the management of input/output (I/O) subsystems in virtual I/O servers to provide appropriate quality of services (QoS). A hierarchical QoS scheme based on partitioning of network interfaces and I/O subsystems transaction types are used to classify Virtual I/O communications. This multi-tier QoS method allows virtual I/O servers to be scalable and provide appropriate QoS granularity.
1 . A method, comprising
maintaining a connection, over a network fabric, to a virtual storage network interface layer of an application server, wherein the virtual storage network interface layer is associated with a virtual storage node identifier;
presenting, at a physical storage network interface, the virtual storage node identifier to a storage area network;
enforcing a hierarchical token bucket resource allocation of bandwidth across the physical storage network interface;
receiving, over the connection, a storage command from the virtual storage network interface layer of the application server, wherein the storage command is a command to read data from, or write data to, a target connected to the storage area network;
determining a data transfer size associated with the storage command;
classifying the storage command relative to the hierarchical token bucket resource allocation to determine a current amount of tokens available;
comparing the data transfer size of the storage command to the current amount of tokens available;
processing the storage command, if the current amount of tokens available are sufficient;
forwarding the data associated with the storage command to the destination; and
buffering the storage command, if the current amount of tokens available are insufficient.