A data layout mechanism is described for allocating metadata within a storage system employing data striping. The data layout mechanism includes a number of storage devices, each of the storage devices having storage spaces allocated to store individual data stripe units associated with a number of stripes. The data layout mechanism further includes a plurality of metadata chunks allocated within the storage devices such that (1) metadata associated with at least two data stripe units of the same stripe is stored within a single metadata chunk, and (2) the metadata chunks are evenly distributed across the storage devices.

Method and system for striping data to accommodate integrity metadata

A system, method, and article of manufacture are provided for efficiently retrieving data. A total amount of data required for an application executed by a client is determined. In a single call, the total amount of data from a server is requested over a network. All of the data is bundled into a data structure by the server in response to the single call. The bundled data structure is sent to the client over the network and the data of the data structure is cached on the client. The cached data of the data structure is used as needed during execution of the application on the client.

Efficient server side data retrieval for execution of client side applications

Method and apparatus for copying, transferring, backing up and restoring data are disclosed. The data can be copied, backed up or restored in segments sizes larger than the data blocks which comprise a logical object. In some embodiments, the segment can correspond to a track of a primary storage device and the data blocks to a fixed size block. In some instances, copying, storage and transfer of the segments which include multiple data blocks can result in transfer of a data block not in a logical object.

Apparatus and methods for copying, backing up, and restoring data using a backup segment size larger than the storage block size

Methods, systems, and configured storage media are provided for flexible data mirroring. In particular, the invention provides many-to-one data mirroring, including mirroring from local servers running the same or different operating systems and/or file systems at two or more geographically dispersed locations. The invention also provides one-to-many data mirroring, mirroring with or without a dedicated private telecommunications link, and mirroring with or without a dedicated server or another server at the destination(s) to assist the remote mirroring unit(s). In addition, the invention provides flexibility by permitting the use of various combinations of one or more external storage units and/or RAID units to hold mirrored data. Spoofing, SCSI and other bus emulations, and further tools and techniques are used in various embodiments of the invention.

Flexible remote data mirroring

Performing data management operations on replicated data in a computer network. Log entries are generated for data management operations of an application executing on a source system. Consistency point entries are used to indicate a time of a known good, or recoverable, state of the application. A destination system is configured to process a copy of the log and consistency point entries to replicate data in a replication volume, the replicated data being a copy of the application data on the source system. When the replicated data represents a known good state of the application, as determined by the consistency point entries, the destination system(s) may perform a storage operation (e.g., snapshot, backup) to copy the replicated data and to logically associate the copied data with a time information (e.g., time stamp) indicative of the source system time when the application was in the known good state.

Systems and methods for performing data replication

An incremental backup system includes a storage unit, which is accessed in block units of a predetermined size, for storing data to be backed up. Difference map information stored in the storage unit records the latest backup generation number, indicating when data in each block has been updated. A latest update generation management mechanism manages backup generation numbers for each block. A difference management mechanism inputs and stores backup data in a backup unit. The backup data includes data in a block of the storage unit which is updated in a specified backup generation based on the difference map information, a position of the block in the storage unit, and a backup generation in which the block has been updated.

Incremental backup system

Data transmission system and methods in which data is automatically selected based upon, the processing ability of a client and the condition of a data transmission line connecting a server and the client. A terminal attribute unit that collects ability characteristics of the client and a line controller that collects the transmission rate of the data transmission line are provided in the server. A data attribute provider provides a proper data type and data amount of transmitting data in a profile based upon the collected information about the client. A data transmission agent refers to a correspondence table and selects data having a proper data amount. Then, the data transmission agent transmits the selected data to the client.

Client-optimized data transmission system and method

The invention provides an exclusive control unit among computers which can reliably perform an exclusive control for a shared resource while keeping a system running as a whole even if a problem occurs in any of the computers in the system. Each of the computers is connected to the others through a LAN and to a distributed shared memory bus for connecting each distributed shared memory card mounted on each computer with the others. The distributed shared memory card has a distributed shared memory, which shares the shared resource with the other distributed shared memories, and a distributed shared memory controller which is connected with the distributed shared memory bus for making it possible to exchange data among the distributed shared memories mounted on the computers, an I/O bus inside its own computer, and its distributed shared memory, through its internal bus, and the distributed shared memory card performs an exclusive control for the shared data which is shared among the respective computers and exchanged among them through the distributed shared memory bus.

Exclusive control unit for a resource shared among computers

A cache memory having four user memory areas in which different data in a main memory is to be respectively stored, and a system memory area in which shared data between programs in the user memory areas is to be stored A data controller has a route register in which address information, such as information as to whether or not the data in the respective user memory area is replaceable and task information, is to be stored The individual user memory areas are connected to one another via a cache internal address data bus and a user-area cache internal sub-address data bus The internal bus is connected to a CPU bus and a memory bus via a memory management unit for performing address translation, etc

Cache memory system having at least one user area and one system area wherein the user area(s) and the system area(s) are operated in two different replacement procedures

Jose Uemura

Papers

Incremental backup system

Client-optimized data transmission system and method

Exclusive control unit for a resource shared among computers

Cache memory system having at least one user area and one system area wherein the user area(s) and the system area(s) are operated in two different replacement procedures