Abstract: Technology is disclosed for stack isolation in a storage system including a storage network switch and multiple storage sub-systems (e.g., storage stacks). The storage network switch includes multiple ports and at least one of the ports is configured to dynamically connect to a device that can be either a storage controller device or a storage sub-system. The technology can receive an identification message indicating that a device is connected to a port of a storage network switch, determine based on the identification message at the storage network switch whether the device is a storage controller device or a storage sub-system, and transfer messages between the ports of the storage network switch such that the storage network switch prevents communications between storage sub-systems connected to the storage network switch, but allows communications between the storage sub-systems and storage controller devices connected to the storage network switch.

Abstract: Technology is disclosed for stack isolation in a storage system including a storage network switch and multiple storage sub-systems (e.g., storage stacks). The storage network switch includes multiple ports and at least one of the ports is configured to dynamically connect to a device that can be either a storage controller device or a storage sub-system. The technology can receive an identification message indicating that a device is connected to a port of a storage network switch, determine based on the identification message at the storage network switch whether the device is a storage controller device or a storage sub-system, and transfer messages between the ports of the storage network switch such that the storage network switch prevents communications between storage sub-systems connected to the storage network switch, but allows communications between the storage sub-systems and storage controller devices connected to the storage network switch.

Abstract: A method and system for batching commands and status information between a host computer and an adapter installed on the host computer. The method for command batching includes the host storing command pointers, each command pointer pointing to a command in an array, and providing an array pointer to the array. When a predetermined threshold of stored commands has been reached, the host can deliver a multitude of commands via the array pointer with a single bus access. A method for status batching includes transferring command statuses from the adapter to the host computer and providing a pointer to the transferred statuses. When a predetermined threshold of statuses has been reached, the adapter interrupts the host computer once to fetch the pointer and the host can then read the statuses without requiring any more bus interrupts.

Abstract: An information handling system transfers command blocks between a host processing side having a host processing unit and a host memory and a local processing side having a local processing unit and a local memory. The command blocks are transferred from the host processing side to the local processing side by storing the host address of the command block in a local side register set. Upon storing the host address a transfer signal is given to a command block transfer controller to start a command block transfer without the local processor unit intervention.

Abstract: An information handling system transfers command blocks between a host processing side having a host processing unit and a host memory, and a local processing side having a local processing unit and a local memory. The local memory includes a command address queue portion for queuing local command address images containing the local addresses of the command blocks. A command block transfer controller is responsive to the local command address images for storing the transferred command block into a corresponding portion of the local memory.

Abstract: An information handling system transfers data blocks between a host processing side having a host processing unit and a host memory and a local processing side having a local processing unit and a local memory. The host memory includes a status queue memory portion having a plurality of status queue images each image storing a status information relating to a corresponding data transfer. The status information relating to data block transfers are posted on the host processing side. The host processing unit, upon system initialization, sets up a status queue register set within the local processing side defining status queue parameters including the location of the status queue memory portion within the host memory and pointer values pointing to where status queue images are to be stored and from where they are to be retrieved.

Abstract: An information handling system transfers data blocks between a host processing side having a CPU and a host memory and a local processing side having a local processing unit and a local memory. The local memory includes a DCB queue memory portion having a plurality of DCB images each image defining host and local addresses of a corresponding data transfer. The DCB images also store a default status condition representing the most likely condition of a data transfer which in the preferred embodiment is a no error condition. A data transfer status detector determines whether the default status condition is true or false. If true, the default status information relating to a corresponding data block transfer is posted on the host processing side without local processing unit intervention.