Emc IP Holding Company LLC

Alan Rajapa

Arieh Don

Erik P Smith

Scott Rowlands

Igor Fradkin

James L Davidson

Mark C Lippitt

Massarrah N Tannous

Jean Evans Pierre

Bandwidth consumption for IO paths between a storage system and host may be managed. It may be determined whether there is congestion on a front-end port (FEP) link. For example, the storage system may monitor for a notification from the switch in accordance with a Fibre Channel (FC) protocol. If a notification is received indicating congestion on an FEP link, the bandwidth thresholds (BWTs) for one or more IO paths between the storage system and one or more hosts that include the FEP link may be reduced. The host port BWTs may continue to be reduced until a congestion notification communication has not been received for a predetermined amount of time, in response to which the host port BWTs for one or more host port links on IO paths that include the FEP link may be increased. Similar techniques may be employed for an FEP link determined to be faulty.

Managing IO path bandwidth

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.

Managing I/O connectivity issues

Storage-based slow drain detecting and automated resolution is provided herein. A data storage system as described herein can include a memory that stores computer executable components and a processor that executes computer executable components stored in the memory. The computer executable components can include a switch query component that obtains a host transfer rate negotiated between a host device and a network switch from a host-connected port of the network switch; a comparison component that compares the host transfer rate to an array transfer rate negotiated between the network switch and a storage array; and a rate limiter component that limits a data transfer from the storage array to the host device to the host transfer rate in response to the host transfer rate being less than the array transfer rate.

Storage-based slow drain detection and automated resolution

A topology service may include a topology database and topology service interface used by clients to query the topology database. The topology database may describe a topology of resources of an infrastructure that may include racks of resources such as network, compute and storage resources. The topology database may be populated using discovery information returned as a result of issuing discovery requests to switches. The discovery information may identify connectivity between switches and other resources. The discovery information may be processed to determine assigned switch roles and additional derived information such as regarding instances of topological entities in the infrastructure. The derived information may identify instances of racks, rows and data centers in the infrastructure. The topology database may identify particular resources included in the different racks, rows, and data centers as well as connectivity between resources and communication capabilities of resource interfaces.

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North Smithfield, RI, United States of America

Alan Rajapa