摘要:
An apparatus, system, and method are disclosed for efficient creation of point-in-time versions of data using differencing in a read-before-write environment. Included in an embodiment of the invention are a receive module that receives a data block sent from a primary data storage system, a read module that reads a data block from a secondary data storage device into random access memory, the data block corresponding to the data block sent from the primary data storage system, a comparison module that compares the data block sent from the primary data storage system to the data block from the secondary data storage device and creates a differencing data file, a compression module that compresses the differencing data file and to create a compressed differencing data file, and a differencing storage module stores the compressed differencing data file in a differencing storage device.
摘要:
Provided are a method, system and program for prefetching data into cache. A prefetch command is processed that indicates at least one conditional statement and at least one block to prefetch from storage to cache in response to determining that the conditional statement is satisfied.
摘要:
A network component useful in tracking write activity by writing logs containing write address information is described. The tracking component may be used in networked systems employing data mirrors to record data block addresses written to a primary storage volume during the time a data mirror is unavailable. The tracking component can be available to any network originating node, and may therefore track write activity on multiple volumes. At the time a data mirror is reconstructed, the log written may be used to construct a list of block addresses pointing to locations on a primary storage volume wherein data differs from a secondary storage volume member of the mirror. The locations maybe copied from the primary to secondary storage volume to reconstruct the data mirror. The performance impact of the tracking component is minimal and a shared network resource is offered that increases fault tolerance in the event of backup device failures.
摘要:
A method to select a captain control node from a plurality of interconnected control nodes is disclosed. The method provides by each of the plurality of control nodes a first signal to each of the other control nodes, and then receives by each of the plurality of control nodes, a response signal from each of the other control nodes. The method then calculates by each of the plurality of control nodes individual response times for each of the other control nodes, and determines by each control node its aggregate response time. The method then determines whether to select a captain control node using the aggregate response times. If the captain control node is selected using the aggregate response times, then the method then determines the minimum aggregate response time, and designates the control node having that minimum aggregate response time the captain control node.
摘要:
An apparatus, system, and method are disclosed for switching a volume address association in a point-in-time copy relationship. A copy module creates a point-in-time copy structure of a source volume at a target volume. A migration module copies data from the source volume to the target volume. A detection module detects data corruption in the source volume. A switch module switches a logical volume address from a source volume address of the source volume to a target volume address of the target volume in response to detecting the data corruption, redirecting data reads and writes to the target volume. In one embodiment, a tracking module tracks a current target volume copy of source volume data and redirects an access for source volume data without the current target volume copy to the source volume.
摘要:
Provided are a method, system, and program for establishing copy relationships to copy source data to target data. A request is received to establish a copy relationship indicating to copy source data to target data. A determination is made as to whether the source data defined in the request comprises target data defined in a preexisting copy relationship. A determination is made as to whether base source data copied to the target data in the preexisting copy relationship also comprises the source data indicated in the request in response to determining that the source data defined in the request comprises target data in the preexisting copy relationship. A new copy relationship is defined to copy the determined base source data to the target data indicated in the request.
摘要:
Disclosed is a technique for data synchronization. A first identifier for a portion of data on a primary volume is determined, wherein a unique identifier is associated with each portion of data at the primary volume. A second identifier for a portion of corresponding data at a secondary volume is determined, wherein a unique identifier is associated with each portion of data at the secondary volume. The first and second identifiers are compared. When the first and second identifiers do not match, the portion of corresponding data at the secondary volume in a storage device is replaced with the portion of data at the primary volume.
摘要:
Provided are a method, system, and article of manufacture, wherein a controller receives a request from one of a plurality of hosts. The controller determines whether a primary storage control unit coupled to the controller is operational. A response is generated by accessing the primary storage control unit, in response to determining that the primary storage control unit is operational. The response is generated by accessing a secondary storage control unit, in response to determining that the primary storage control unit is not operational, wherein data is replicated synchronously from the primary storage control unit to the secondary storage control unit.
摘要:
A system, method and computer program product are provided to improve the efficiency of the transmission of consistency groups across multiple storage components by ensuring that volume transactions are evenly allocated among backup components. Each volume is initially assigned to a specified backup component. Once a color period begins, volume transactions are transmitted to the assigned backup component. Each backup component accumulates data transfer information for its assigned volumes throughout at least a portion of the color period and calculates a new volume assignment for the next color period. Before the start of the next color period, a captain storage controller transmits any new assignments to the backup components. During a next color period, the process is repeated using the new assignments.
摘要:
A method to optimize the transmission of data from (N) primary backup appliances interconnected to a plurality of second backup appliances by a single communication link, wherein (N) is greater than 1, by transferring a data set to one or more secondary backup appliances by two or more of the (N) primary backup appliances using the communication link, and completing those transfers of the data sets by the two or more primary backup appliances at the same time.