Abstract: An apparatus in an illustrative embodiment comprises at least one processing device that includes a processor coupled to a memory. The at least one processing device is configured to implement a centralized discovery controller for coupling to a host and to a storage system accessed by the host, with the centralized discovery controller being configured to receive from the host a congestion alert, and responsive to the received congestion alert, to send to the host and to one or more targets of the storage system corresponding congestion control messages. The congestion alert is illustratively received in the centralized discovery controller from a multi-path input-output (MPIO) driver of the host, where the MPIO driver controls delivery of IO operations from the host to the storage system over selected paths. The congestion control messages may comprise respective Asynchronous Event Notifications (AENs) associated with respective Asynchronous Event Requests (AERs).

Abstract: Techniques for determining an impact that a congested switch port is having on a network and for estimating a reason as to why the congested switch port is congested are disclosed. Configuration data and performance data from a network are obtained. Based on the configuration data, a shortest path between a storage port and a host port is identified. A particular switch port is also identified as a result of that port being congested. An impact as to how the switch port, due to its congestion in the particular shortest path, is impacting or is being impacted by other switch ports in the network is determined. An alert, which includes information indicating the impact, is triggered.

Abstract: A multiple independent storage fabric SAN system includes a storage system. A first storage fabric includes a first switch device that is directly connected to the storage system, and first host devices that are directly connected to the first switch device and each configured to transmit storage data traffic via the first switch device with the storage system. A second storage fabric is independent from the first storage fabric and includes a second switch device that is directly connected to the storage system and that is not configured to transmit storage data traffic with the first switch device, and second host devices that are directly connected to the second switch device and each configured to transmit storage data traffic via the second switch device with the storage system. The storage system is configured to provide first storage services to each of the first storage fabric and the second storage fabric.

Abstract: A scalable EBOF storage system identifies its storage devices and external physical interfaces, and respective public IP addresses assigned to each external physical interface. The scalable EBOF storage system assigns a respective private IP address to each storage device, private port identifier(s) to the storage devices, and respective public port identifier(s) to each storage device.

Abstract: Techniques for determining an impact that a congested switch port is having on a network and for estimating a reason as to why the congested switch port is congested are disclosed. Configuration data and performance data from a network are obtained. Based on the configuration data, a shortest path between a storage port and a host port is identified. A particular switch port is also identified as a result of that port being congested. An impact as to how the switch port, due to its congestion in the particular shortest path, is impacting or is being impacted by other switch ports in the network is determined. An alert, which includes information indicating the impact, is triggered.

Abstract: Bandwidth consumption and/or an I/O transmission rate on an I/O path between a port of a storage system and a physical host port may be managed, including determining when multiple virtual host ports correspond to (i.e., are mapped to) a same physical host port. This virtual host port mapping information may be used to more accurately determine bandwidth consumption and I/O transmission rates on I/O connections along an I/O path including the physical host port, and to adjust the bandwidth consumption and/or I/O transmission rate on one more of these I/O connections according to bandwidth thresholds and I/O count thresholds defined for the I/O path (e.g., for the Physical host port of the I/O path).

Abstract: An apparatus in one embodiment comprises at least one processing device configured to control delivery of input-output (IO) operations from a host device to a storage system over selected ones of a plurality of paths through a network, and to monitor response times for particular ones of the IO operations sent from the host device to the storage system. The at least one processing device is further configured to interact with the storage system to determine network latency from a viewpoint of the storage system, and responsive to (i) at least a subset of the monitored response times being above a first threshold and (ii) the network latency from the viewpoint of the storage system being above a second threshold, to at least temporarily modify a manner in which additional ones of the IO operations are sent from the host device to the storage system.

Abstract: Information pertinent to a connectivity issue reported by a switch may be determined, compiled and reported; and action may be taken autonomously to address the connectivity issue based on the information. The additional information may be determined by the storage system, including querying a switch in response to the switch notifying the storage system of the I/O error, and the storage system accessing one or more data structures to determine additional information. The storage system may cause I/O communications on the I/O path to be at least temporarily diverted. For example, in response to receiving an I/O request on the I/O path corresponding to the connectivity issue, the storage system may send a communication to the host system that causes the host system not to send additional I/O requests on the I/O path, at least temporarily, as described in more detail elsewhere herein.

Abstract: An apparatus in one embodiment comprises at least one processing device configured to control delivery of input-output (IO) operations from a host device to a storage system over selected ones of a plurality of paths through a network, and to monitor response times for particular ones of the IO operations sent from the host device to the storage system. The at least one processing device is further configured to interact with the storage system to determine network latency from a viewpoint of the storage system, and responsive to (i) at least a subset of the monitored response times being above a first threshold and (ii) the network latency from the viewpoint of the storage system being above a second threshold, to at least temporarily modify a manner in which additional ones of the IO operations are sent from the host device to the storage system.

Abstract: An apparatus comprises a host device configured to communicate over a network with a storage system. The host device comprises a plurality of host bus adaptors, and a multi-path input-output driver configured to control delivery of input-output operations from the host device to the storage system over selected ones of a plurality of paths through the network. The paths are associated with respective initiator-target pairs wherein each of the initiators comprises a corresponding one of the host bus adaptors and each of the targets comprises a corresponding one of a plurality of ports of the storage system. The host device monitors performance of the ports in processing input-output operations delivered thereto, detects an initiator-related condition based at least in part on the monitored performance, and automatically adjusts an assignment of one or more of the initiators to one or more of the targets based at least in part on the detected initiator-related condition.

Abstract: Single points of failure (SPoFs) may be determined for I/O connectivity on a storage network. I/O path information may be determined for a storage device, for example, as a result of a host system logging into the storage network, and may be updated in response to events on the storage network. From this determined I/O path information, one or more SPoFs between a storage device and an application layer may be determined if, for the I/O path information collectively, it is determined that there is only one of any of the path components between the storage device and the application layer. The I/O path information may be displayed in a manner that facilitates a user identifying that there is an SPoF on an I/O path between a storage device and an application layer of a host system. Based on the determination of an SPoF, an alert may be issued.

Abstract: Bandwidth consumption and/or an I/O transmission rate on an I/O path between a port of a storage system and a physical host port may be managed, including determining when multiple virtual host ports correspond to (i.e., are mapped to) a same physical host port. This virtual host port mapping information may be used to more accurately determine bandwidth consumption and I/O transmission rates on I/O connections along an I/O path including the physical host port, and to adjust the bandwidth consumption and/or I/O transmission rate on one more of these I/O connections according to bandwidth thresholds and I/O count thresholds defined for the I/O path (e.g., for the Physical host port of the I/O path).

Abstract: Information pertinent to a connectivity issue reported by a switch may be determined, compiled and reported; and action may be taken autonomously to address the connectivity issue based on the information. The additional information may be determined by the storage system, including querying a switch in response to the switch notifying the storage system of the I/O error, and the storage system accessing one or more data structures to determine additional information. The storage system may cause I/O communications on the I/O path to be at least temporarily diverted. For example, in response to receiving an I/O request on the I/O path corresponding to the connectivity issue, the storage system may send a communication to the host system that causes the host system not to send additional I/O requests on the I/O path, at least temporarily, as described in more detail elsewhere herein.

Abstract: Bandwidth on a front-end port of a storage system may be managed. A plurality of logical storage units may be divided into a plurality of priority groups according to a predefined priority. For a first priority group of the plurality of priority groups having a highest priority, a first forecasted average amount of bandwidth of the first port to be consumed by the logical storage units of the first priority group during a first temporal interval may be determined. Based on the first forecasted average amount, a first reserve amount of bandwidth on the first port to be reserved for use by the logical storage units of the first priority group during the first temporal interval may be determined. The first reserve amount of bandwidth on the first port for use by the logical storage units of the first priority group during the first temporal interval may be reserved.

Abstract: Bandwidth on a front-end port of a storage system may be managed. A plurality of logical storage units may be divided into a plurality of priority groups according to a predefined priority. For a first priority group of the plurality of priority groups having a highest priority, a first forecasted average amount of bandwidth of the first port to be consumed by the logical storage units of the first priority group during a first temporal interval may be determined. Based on the first forecasted average amount, a first reserve amount of bandwidth on the first port to be reserved for use by the logical storage units of the first priority group during the first temporal interval may be determined. The first reserve amount of bandwidth on the first port for use by the logical storage units of the first priority group during the first temporal interval may be reserved.

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: 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: Techniques for determining connectivity may include: defining predetermined configurations, each including a predetermined zoning configuration of a network and selection criteria indicating when to transition into and activate the predetermined configuration; loading the predetermined configurations; activating a first of the predetermined configurations that includes a first predetermined zoning configuration and first selection criteria; receiving current I/O workload and/or performance information for the network; determining whether the current I/O workload and/or performance information for the network matches second selection criteria associated with a second of the predetermined configurations that is different from the first predetermined configuration currently activated; and responsive to determining the current I/O workload and/or performance information matches the second selection criteria, activating the second predetermined configuration that is different from the first predetermined configura

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: Techniques for transmitting data may include: receiving, at a host, an initiator data transfer rate indicating a communication rate at which an initiator port of the host communicates over a first path using a communications fabric with a target port of a data storage system; receiving, at the host, a target data transfer rate indicating a communication rate at which the target port of the data storage system communicates over the first path using the communications fabric with the initiator port of the host; determining, at the host, whether the initiator data transfer rate and the target data transfer rate are different; and responsive to determining that the initiator data transfer rate and the target data transfer rate are different, performing processing that limits a rate at which data is transmitted between the initiator and target ports in accordance with the initiator and target data transfer rates.