Latency reduction associated with a response to a request in a storage system

摘要

A method includes segmenting a virtual volume into an active area configured to map to a first type of storage and a non-active area configured to map to a second type of storage through a storage virtualization engine. The second type of storage includes data associated with a host device and the first type of storage includes point-in-time images corresponding to the data associated with the host device. The first type of storage offers a higher performance than that of the second type of storage. The method also includes allocating a portion of space in the first type of storage to serve as a cache memory during a write operation and/or a read operation, and reducing a latency associated with the response to a write request and/or a read request through performing the corresponding write operation and/or the read operation through the first type of storage.

主权项

1. A method comprising:
segmenting a virtual volume into an active area configured to map to a first type of storage and a non-active area configured to map to a second type of storage through a storage virtualization engine, the second type of storage configured to include data associated with a host device and the first type of storage configured to include point-in-time images corresponding to the data associated with the host device, the first type of storage being a faster type than the second type of storage the first type of storage and the second type of storage both being in an active state, and the storage virtualization engine being configured to map the virtual volume to storage locations in the first type of storage and the second type of storage; allocating a portion of space in the first type of storage to serve as a cache memory during both a write operation and a read operation in response to a corresponding write request and a read request through the host device; initializing, through the storage virtualization engine, read-only maps associated with the point-in-time images in the first type of storage to indicate a “no permission” status in response to the read request such that the read request faults; enabling copying, through the storage virtualization engine, an appropriate portion of data from both the first type of storage and the second type of storage regardless of the mapping thereof to the active area or the non-active area following the faulting of the read request in accordance therewith, the appropriate portion of data being resident in one of the first type of storage and the second type of storage; and reducing a latency associated with the response to the write request and the read request through performing the write operation and the read operation solely through the first type of storage, the write operation including caching data to be written to the second type of storage at the first type of storage, and the read operation including fetching the appropriate portion of data to an appropriate cache location in the first type of storage to be read therefrom regardless of whether the appropriate portion of data is copied from the second type of storage or the first type of storage.