Abstract: An improved system and method for handling input/output (I/O) data transfers between storage devices and file systems is disclosed. The file system is made aware of the geometry of the storage device either through automatic querying of the storage device or through user input. The file system then intelligently employs the information about the geometry of the storage device to optimize data storage transfers between the file system and the storage device. The optimization may involve, for instance, storing volume header information in full array subsystem stripes, making disk and object geometry available in volume headers, accessing and applying volume set configuration parameters, placing file directory information at strip/stripe boundaries, strategically placing blocks and clusters of data, and applying knowledge of locking segment size.

Abstract: The invention provides a system, apparatus and procedure whereby a controller manages computer access to a number of storage volumes in a storage peripheral. To accomplish this, a system administrator assigns a plurality of port IDs to a disk array controller, the disk array controller being responsive to requests from a computer using any of the plurality of port IDs. Next, the system administrator configures a data structure in a memory of the controller such that at least a subset of the plurality of port IDs are mapped to particular ones of the number of storage volumes. Next, in response to an access request by a computer, wherein the access request specifies a target port ID, the controller grants the computer access to only those storage volumes whose mapped port ID corresponds to the target ID.