Abstract: Methods and systems are disclosed that relate to selecting a path for sending an I/O request from a host to a data storage subsystem from among a plurality of paths from the host to the subsystem. An exemplary method includes identifying a limitation on the traffic level for the plurality of paths, tracking a first metric corresponding to the limitation on the traffic level for each path, and transmitting a first I/O request having an urgency level other than the highest urgency level by one of the plurality of paths whose first metric does not exceed its limitation on the traffic level.

Abstract: Systems and methods are provided for disabling a device in an enterprise storage system. In one embodiment, a method comprises receiving information identifying a device in a storage area network that is scheduled for an outage. The method further determines one or more paths impacted by the outage of the device, generates a notification identifying the determined one or more paths, and transmits the notification to one or more hosts having paths to the device.

Abstract: Methods and apparatus for non-disruptive upgrade by redirecting I/O operations. With this arrangement, a driver upgrade does not require restarting an application. In one embodiment, a method includes installing on a computer a legacy upgrade module in a kernel having a legacy driver with first and second loadable extensions for handling input/output operations for applications to and from devices, retrieving and storing static configuration data from the legacy driver, transferring the stored static configuration data to a new driver, obtaining runtime device configuration data from the devices and transferring the runtime device configuration data to the new driver, and filtering device input/output operations such that prior to cutover input/output operations are directed by the LUM through device stacks for the legacy driver and after cutover input/output operations are directed to the new driver.

Abstract: Systems and methods are provided for executing a vendor specific command in a storage area network including a plurality of data storage volumes and at least one host. In one embodiment, a system includes an intelligent multi-protocol switch (IMPS) and a storage and switch controller that is coupled to the IMPS. The IMPS receives a command from the at least one host. The command includes a command byte field storing a vendor specific service action. The storage and switch controller receives the command from the IMPS. A processor included in the storage and switch controller interprets the vendor specific service action and executes the command.