The present invention provides a technique for, in the case in which a failure has occurred in a shared memory, controlling a period of a pseudo through operation to reduce a period in which performance of a disk array device falls. Control information is divided into management information, which is required to be duplexed, and directory information, which is only required to simplexed, and the management information and the directory information are stored in separate shared memories. In the c...

In an embodiment, a method for an adaptive address space operating system, includes: selecting a first model of the address space layout for a process; attempting to perform an operation within a virtual address; determining if the operation can be performed successfully based on the first model or based upon a second model; if the operation cannot be performed successfully based upon the first model but can be performed successfully based upon the second model, then converting the address space...

A pointer comparing unit determines whether a value of a writing pointer is identical to a value of a reading pointer. When it is determined that the value of the writing pointer is different from the value of the reading pointer, an inter-memory transfer unit reads data stored in a location where a data transfer apparatus reads transmission data from a transmission ring buffer, transfers the data to a reception memory, and writes the data in a location designated by the reading pointer of a rec...

A method, apparatus, and computer instructions are provided for storage provisioning automation in a data center. A storage manager is provided in the present invention to facilitate end-to-end deployment of storage resources for a server in the data center. The storage manager includes functionalities of a volume manager, file system, and physical volumes. In addition, a hierarchical structure is provided by the present invention to specify configuration data for a volume container. The hierarc...

Methods and apparatus allowing a choice of Least Frequently Used (LFU) or Most Frequently Used (MFU) cache line replacement are disclosed. The methods and apparatus determine new state information for at least two given cache lines of a number of cache lines in a cache, the new state information based at least in part on prior state information for the at least two given cache lines. Additionally, when an access miss occurs in one of the at least two given lines, the methods and apparatus (1) se...

A technique enables application data stored on storage devices of a storage system to be accessible by a client as either a file or logical unit number (lun). The storage system is illustratively embodied as a multi-protocol storage appliance having a storage operating system that implements a file system. The file system logically organizes the application data as a virtual disk (vdisk) comprising a plurality of inodes including a prefix stream inode, a lun inode (storing the application data) ...

An invention is provided for using a comparand provided to a CAM for multiple CAM operations without requiring the comparand to be reloaded from a host processor for each CAM operation. The invention includes a comparand data register that is capable of storing a comparand. Associated with the comparand data register, is a plurality of result registers. In operation, the comparand is provided as input data to the CAM for a plurality of search operations. For each search operation, the result is ...

A method, apparatus, and computer instructions in a processor for associating a data type with a memory location. The type is associated with a location by means of metadata that is generated and manipulated by hardware instructions that are typically generated by a compiler as it generates the other instructions that comprise the machine code version of a program. A determination is made as to whether a data value about to be stored is of the required data type for that location. The hardware i...

The efficient performance of prefetching of data prior to the reading of the data by a program. A prefetching apparatus, for prefetching data from a file to a buffer before the data is read by a program, includes: a history recorder, for recording a history for a plurality of data readings issued by the program while performing data reading; a prefetching generator, for generating a plurality of prefetchings that correspond to the plurality of data readings recorded in the history; a prefetching...

An apparatus for reducing data unavailability time after a loss of main power in a storage controller is described. The controller backs up its volatile memory containing posted-write data to a non-volatile memory upon detecting a loss of main power. The controller continues to provide battery power to the volatile memory to sustain the posted-write data. If the battery is able to supply power to the volatile memory until main power is restored, the controller foregoes restoring the posted-write...