摘要:
This invention is a system and method for simulating performance of one or more data storage systems. This invention may be used in many useful ways including for configuring or modeling a data storage environment, problem isolation, and general design.
摘要:
Described are techniques for caching. At a first point in time, a first set of data portions currently stored in a first cache of a first data storage system is determined. Each data portion of the first set is located on a first device of the first data storage system. Sent to a second data storage system is first information including information identifying a storage location on the first device for each data portion of the first set. The second data storage system includes a second device that is maintained as a mirror of the first device. The storage location for each data portion of the first set is used to identify a second storage location of the second device corresponding to the storage location. The first information is used to populate a second cache of the second data storage system.
摘要:
This invention is a system and method for configuring a data storage system based on workload, response time, or utilization requirements. The method includes the steps of receiving workload, utilization or response time data, analyzing the respective received data, determining a configuration for a data storage system which may be available in report form to a user.
摘要:
A method for implementing the invention is carried out in a data-storage system having a data storage unit that includes at least two constituent data storage elements. Each of the constituent data storage elements is either in a first state or a second state. The method includes providing a data structure having an entry corresponding to the data storage unit. The entry includes status information indicating whether at least one constituent data storage element of the data storage unit is in the first state. These entries are updated as necessary following any changes in state of the constituent data storage element. Scanning the data storage units instead of the data storage elements provides a more efficient way to locate data storage elements in the first state, particularly where such data storage elements are rare.
摘要:
Providing quality of service levels to a plurality of sources that perform access requests to a disk resource includes providing a disk resource queue containing access requests for the disk resource, providing a source queue for each of the sources containing access requests generated by a corresponding one of the sources, determining if a new access request from a particular source is urgent according to a specified number of I/O operations per second for the particular source and a time since a previous access request from the particular source, adding the new access request to the disk resource queue if the new access request is urgent, and adding the new access request the source queue of the particular source if the new access request is not urgent and the length of the disk resource queue is greater than a predetermined queue depth value.
摘要:
Destaging activities in a data storage system are controlled by providing a write pending list of elements, where each element is defined to store information related to a cache memory data element for which a write to storage is pending, and maintaining the write pending list so that destaging of a data element can be based on the maturity of the pending write.
摘要:
Techniques are described for determining data movements. Gradient sets are determined for storage tiers. Each gradient set is associated with one of the storage tiers and includes at least one gradient. Based on the gradient sets, a donor tier and a first set of one or more receiving tiers are selected from the plurality of storage tiers. A first data portion having data currently stored on at least one physical device of the donor tier is selected. In accordance with data movement criteria, a second data portion included in a receiving tier of the first set is selected. Selecting the second data portion includes modeling a first data movement including moving the first data portion from the donor tier to the receiving tier. The first data movement may be included in a recommended list and may be performed by a data storage optimizer.
摘要:
Synchronization of data layouts and resource utilizations at one or more remote replica sites with the workload and data tiering decisions being made at the primary site allows for an efficient and effective workload support transfer in the event of site failover from a primary site to a remote site. Relevant data access information about workload being supported at the primary site is collected and from that raw information, characterized data access information is generated that condenses the raw data access information or otherwise provides relevant encapsulated information about the raw data access information. The characterized data access information is transmitted to the one or more remote sites allowing each remote site to make its own independent decisions on how best to utilize its available resources to match the performance requirements currently being supported by the primary site.
摘要:
Described are techniques for storing first data to a logical data in accordance with a static policy to service reads using data stored in a first storage area. The logical device has its data stored on a first physical device that is mirrored on a second physical device. Each of the first and second physical devices include a first storage area and a second storage area. The first storage areas provide better performance than the second storage areas. The first data is stored at a first location in one of the first storage areas of one of the physical devices and at a second location in one of the second storage areas at the other of the first and the second physical devices. An operation to read the first data is serviced by accessing the first data stored in the first area of the one physical device.
摘要:
Measuring access rates of a computer memory include subdividing the memory into subsections, monitoring access rates for each of the subsections, in response to a subsection having a relatively high access rate, subdividing the subsection into multiple subsections that are separately monitored, and, in response to at least two adjacent subsections having a relatively low access rate, merging the at least two subsections into a single subsection. Monitoring access rates may include monitoring at least one of the following operational parameters: number of data accesses, number of cache accesses, number of cache misses, number of read accesses, number of write accesses, and ratio of read accesses to write accesses. Two or more operational parameters may be used and the operational parameters may be weighted.