A storage area network associated data library partitioning system comprises a plurality of storage slot elements adapted to store data storage media, at least one set of at least one of the slots is assigned to one partition of a plurality of partitions, and a plurality of data transfer elements that are adapted to receive the media and transfer data to and from the media, each of at least one set of at least one of the data transfer elements is assigned to one of the partitions, at least one data transfer element of each of the partitions hosts a logical element designation of a virtual controller for each of the partitions, the virtual controllers restricting movement of the media to between the set of slots and the set of data transfer elements assigned to a same of the partitions.
In response to multiple data transfer requests from an application, a data definition (DD) chain is generated. The DD chain is divided into multiple DD sub-blocks by determining a bandwidth of channels (BOC) and whether the BOC is less than the DD chain. If so, the DD chain is divided by the available DMA engines. If not, the DD chain is divided by an optimum atomic transfer unit (OATU). If the division yields a remainder, the remainder is added to a last DD sub-block. If the remainder is less than a predetermined value, the size of the last DD sub-block is set to the OATU plus the remainder. Otherwise, the size of the last DD sub-block is set to the remainder. The DD sub-blocks are subsequently loaded into a set of available DMA engines. Each of the available DMA engines performs data transfers on a corresponding DD sub-block until the entire DD chain has been completed.
A storage controller that provides controlled access to storage devices by host computers is disclosed. The storage controller includes a host interface adapter that interfaces the storage controller to the hosts, a device interface adapter that interfaces the storage controller to the storage devices, and a microprocessor that processes requests by the hosts to access the storage devices. An access control table is created in response to user input in a memory accessible by the host interface adapter. When the host interface adapter receives a request, it determines from the access control table whether the requesting host has permission to access the specified storage device. If so, the host interface adapter forwards the request to the microprocessor. Otherwise, the host interface adapter transmits a response to the host denying access in one embodiment, or in another embodiment, provides an indication to the microprocessor that access should be denied.
A storage configuration is automatically changed depending on a storage configuration change schedule which is defined previously by an administrator. Moreover, it is verified whether a storage configuration can be changed or not at the time designated when the schedule is changed.
A data cache for an iSCSI network caches block-level data from WAN servers for use by clients (e.g., LANs). The cache authenticates itself to the WAN servers, and authenticates clients requesting cache access. Mechanisms are provided to prevent clients from accessing cached data intended for other clients.
