Abstract: Techniques are provided for path management and failure prediction in a multipath environment using target port power levels. One method comprises obtaining, by a first entity that communicates with a second entity via multiple paths, a transmit power level and/or a receive power level of a target port associated with the second entity; evaluating the transmit power level and/or the receive power level of the target port relative to a threshold; and setting, by the first entity, a path state of one or more paths between the first entity and the target port to a standby state based on the evaluating, wherein the first entity establishes paths between the first entity and one or more other target ports of the second entity in an active state. Existing communications on the one or more paths between the first entity and the target port may be allowed to complete in the standby state.

Abstract: A host device comprises a processor coupled to a memory. The host device is configured to obtain from a storage system connectivity information characterizing one or more ports of the storage system, and to automatically establish connectivity of a particular type between the host device and one or more logical storage devices of the storage system based at least in part on the obtained connectivity information. For example, the host device can obtain the connectivity information directly from the storage system or via at least one intermediary device such as a management station. In some embodiments, the obtaining and automatically establishing are performed by at least one multi-path input-output driver of a multi-path layer of the host device. The connectivity of a particular type illustratively comprises Internet Small Computer System Interface (iSCSI) connectivity between the host device and the storage system, although other connectivity types can be supported.

Abstract: Switch topology-aware path selection in an information processing system is provided. For example, an apparatus comprises a host device comprising a processor coupled to a memory. The host device is configured to communicate with a storage system over a network with a plurality of switches. The host device is further configured to obtain topology information associated with the plurality of switches in the network, and select a path from the host device to the storage system through one or more of the plurality of switches based at least in part on the obtained topology information.

Abstract: A host device comprises a processor coupled to a memory. The host device is configured to obtain from a storage system connectivity information characterizing one or more ports of the storage system, and to automatically establish connectivity of a particular type between the host device and one or more logical storage devices of the storage system based at least in part on the obtained connectivity information. For example, the host device can obtain the connectivity information directly from the storage system or via at least one intermediary device such as a management station. In some embodiments, the obtaining and automatically establishing are performed by at least one multi-path input-output driver of a multi-path layer of the host device. The connectivity of a particular type illustratively comprises Internet Small Computer System Interface (iSCSI) connectivity between the host device and the storage system, although other connectivity types can be supported.

Abstract: Communications between a host system and a storage system may be restricted to a single I/O path, at least temporarily, without manually manipulating physical connections to the host system and/or storage system or manually data structures defining I/O connectivity. In response to a communication to maintain only a first permitted I/O path between a host system and a storage system, I/O communications may be prevented on any I/O paths between the host system and the storage system, except for the first permitted I/O system, without modifying the definition of any permitted I/O paths on the storage system. One or more fields may be included in entries of a data structure that defines permitted I/O paths, the fields specifying whether an I/O path should be allowed to, or prevented from, carry communications between a host system and the storage system, at least temporarily.

Abstract: Multiple virtual host ports corresponding to a same physical host port may be determined by or on behalf of a storage system, for example, in response to logging the one or more virtual host ports into the storage system. For one or more virtual host ports, it may be determined whether the virtual host port is connected to a same fabric port as another virtual host port, where a fabric port is a port of a fabric configured to connect to a virtual host port. If two virtual host ports are determined to be connected to a same fabric port, it may be concluded that the two virtual host ports correspond to (e.g., share) a same physical host port. One or more actions may be taken on a storage network based at least in part on a determination that two virtual host ports are sharing a same physical host port.

Abstract: Communications between a host system and a storage system may be restricted to a single I/O path, at least temporarily, without manually manipulating physical connections to the host system and/or storage system or manually data structures defining I/O connectivity. In response to a communication to maintain only a first permitted I/O path between a host system and a storage system, I/O communications may be prevented on any I/O paths between the host system and the storage system, except for the first permitted I/O system, without modifying the definition of any permitted I/O paths on the storage system. One or more fields may be included in entries of a data structure that defines permitted I/O paths, the fields specifying whether an I/O path should be allowed to, or prevented from, carry communications between a host system and the storage system, at least temporarily.

Abstract: Multiple virtual host ports corresponding to a same physical host port may be determined by or on behalf of a storage system, for example, in response to logging the one or more virtual host ports into the storage system. For one or more virtual host ports, it may be determined whether the virtual host port is connected to a same fabric port as another virtual host port, where a fabric port is a port of a fabric configured to connect to a virtual host port. If two virtual host ports are determined to be connected to a same fabric port, it may be concluded that the two virtual host ports correspond to (e.g., share) a same physical host port. One or more actions may be taken on a storage network based at least in part on a determination that two virtual host ports are sharing a same physical host port.