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Method and System for Managing Serial Attached Small Computer System Interface Cables

IP.com Disclosure Number: IPCOM000225593D
Publication Date: 2013-Feb-20
Document File: 5 page(s) / 116K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method and system for managing Serial Attached Small computer system interface (SAS) cables is disclosed.

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This is the abbreviated version, containing approximately 48% of the total text.

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Method and System for Managing Serial Attached Small Computer System Interface Cables

Generally, storage subsystems containing a large number of drive enclosures are connected to associated controller(s) hardware via Serial Attached Small computer system interface (SAS) cables to access and manage disks. Multiple SAS cables are utilized for upstream-downstream as well as front to back rack connections as shown in Fig. 1. In addition, some SAS cables are zoned, which makes detailed cabling even more critical for proper operation. The requirement of a service where multiple cables needs to be unplugged to gain access to a single or multiple enclosures is more problematic. Cables reconnected incorrectly can prevent access to an already established configuration. Generally, all the SAS cables and corresponding enclosures are labeled prior to removal but density of connections and wiring on the enclosures make this approach impractical. Hardware keys such as Small Form Factor 8088 (SFF-8088) are also used to minimize problems with upstream and downstream connections. However, problem arises if there are multiple upstream and downstream connections on the same enclosure. Multiple part number cables of same length with different hardware keys are required and the hardware keys may not specify which enclosure the cable goes to. Rout cables in rack cable management arms also present the same issues as the cables with the hardware keys. Taking pictures prior to unplugging the SAS cables leads to similar issues as the labeling approach.

Figure 1

Disclosed is a method and system for managing SAS cables. The method and system provides a way to map and track connections of SAS cables with enclosures. The method and system provides an interface with a Vital Product Data (VPD) device built into a SAS cable, which contains information about the cable type as well as a unique serial number. The type of SAS cables used can be newly developed mini-SAS-HD such as, but not limited to, SFF-8449, SFF-8636 and SFF-8644. The VPD data can be burned onto a serial Erasable Programmable Read-Only Memory (EEPROM). The

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information about the cable type can be the part number.

The method and system allows mapping of cable configurations via unique software architecture. Using screen management software, the serial number can be accessed via an out of band signal (2WI) qualified with an in-band or a management interface to validate the hardware and zone connection. The management interface can be Ethernet. This provides the user with an opportunity to dynamically re-map zones and cable connections within the configuration. At a physical level, link status Light Emitting Diodes (LEDs) on each port can be used to identify supported connections for the cable configurations as shown in Fig. 2.

Figure 2

A stack of enclosures configured to service a single or multiple hosts, with or without zoning is instructed to capture a map of a SAS topology including...