摘要:
A method, apparatus and program storage device for maintaining data is provided that includes receiving primary data at a first node, receiving mirrored data from a second and third node at the first node, and mirroring data received at the first node to a second and third node.
摘要:
Provided are a method, system, and article of manufacture, wherein a command is received at a first computational device coupled to a first adapter that is capable of allowing access to a data storage to the first computational device. The first computational device sends the command to a second computational device. The command is processed by a second adapter coupled to the second computational device, wherein the second adapter allows the second computational device to access the data storage, and wherein the second adapter accesses memory in the first computational device to process the command. In certain embodiments, the first adapter that allows the first computational device to access the data storage has failed.
摘要:
Provided are a method, system, and program for transferring data directed to virtual memory addresses to a device memory. Indicator bits are set for ranges of device memory addresses in a device accessible over an Input/Output (I/O) bus indicating whether gathering is enabled for the device memory address ranges. Transfer operations are processed to transfer data to contiguous device memory addresses in the device. A determination is made as to whether the indicator bits for the contiguous device memory addresses indicate that gathering is enabled. A single bus I/O transaction is generated to transfer data for the contiguous device memory addresses over the I/O bus in response to determining that the indicator bits for the contiguous device memory addresses indicate that gathering is enabled.
摘要:
A method is disclosed to manage a data cache. The method provides a data cache comprising a plurality of tracks, where each track comprises one or more segments. The method further maintains a first LRU list comprising one or more first tracks having a low reuse potential, maintains a second LRU list comprising one or more second tracks having a high reuse potential, and sets a target size for the first LRU list. The method then accesses a track, and determines if that accessed track comprises a first track. If the method determines that the accessed track comprises a first track, then the method increases the target size for said first LRU list. Alternatively, if the method determines that the accessed track comprises a second track, then the method decreases the target size for said first LRU list. The method demotes tracks from the first LRU list if its size exceeds the target size; otherwise, the method evicts tracks from the second LRU list.
摘要:
Disclosed are a method and apparatus, in a data storage environment with multiple devices sharing data, for writing data to one such device in a manner that indicates that the data need not be destaged to a lower tier of the storage hierarchy. As a specific example, a host computer system may issue a write command to a controller that signals the controller that it is not necessary to destage the data from the controller cache because the data has not been modified by the host. In a preferred embodiment, the controller's cache is an extension of the host's cache, rather than a duplication. To achieve this, the controller needs to know: 1) what data, being requested by the host, is being cached by the host, and should not be cached by the controller, and 2) what data has been cast out of the host's cache, and should now be cached by the controller.
摘要:
An apparatus for limiting volatile computer memory based on available energy in an auxiliary power source comprises an energy monitor module configured to determine an amount of available energy in the auxiliary power source. Also provided is a memory status module configured to determine an amount of volatile computer memory allocated for use in a computer and a memory adjustment module configured to adjust the amount of volatile computer memory allocated for use in the computer based on the amount of available energy in the auxiliary power source. A startup module may be configured to allow the computer to begin moving data normally when the memory adjustment module limits volatile computer memory allocated for use by the computer to a minimum level and the energy monitor module determines that the amount of available energy in the auxiliary power source has reached a minimum level capable of transferring the volatile computer memory allocated for use by the computer to non-volatile computer memory during a computer shutdown.