| 摘要 |
A data storage system establishes streamlined data exchange paths between stored data and multiple system hosts, decreasing contention among the hosts and expediting host access to the data. First, one or more storage directors receive an initial host request to access a data block contained in part of a shared data resource. This part of the shared data resource may comprise a magnetic disk drive device, part of a physical device, a logical volume, a logical device or another data group. In response, the storage director performs a predetermined series of initial access steps to facilitate the data transfer. For example, the data block is copied from the shared data resource into a cache, if not already present therein. Then, a data path is formed between the host and the device containing the data block. Next, a fast path map is updated to indicate establishment of the data path between the host and the device containing the data block. The data block is subsequently exchanged between the cache and the host. When the storage director receives a subsequent request by the same host to access the same device, the storage director consults the fast path map and determines that a data path already exists between the host and the device. Accordingly, the requested data is exchanged between the host and the cache utilizing the previously established data path between the host and the device, avoiding many steps initially required to establish the data path.
|
