1. Field of the Invention
The present invention relates to a support method of supporting cable connection between a controller housing (or unit), which is provided in a disk array device, and plural disk device housings (or units).
2. Description of the Related Art
Plural disk devices are provided in a disk array device. A predetermined number of disk devices among these disk devices are stored in each of disk device housings. In disk array device housing, a controller housing, which contains a controller, and plural disk device housing are stored and connected by a fiber channel each other (see JP-A-9-330184).
Input ports and output ports for connecting cables of the fiber channel are provided in the disk device housings. The fiber channel is connected in loop using these ports. Conventionally, a connection method of forming two loops (hereinafter referred to as “two loop”) has been mainly used such that the plural disk devices can be accessed in parallel.
FIG. 1 is an explanatory diagram showing a backend connection state of a controller housing CTL and disk device housings DISK. In this example, the controller housing CTL has two backend loops (FC-LA loops) which consist of two loops of a loop LP#0 and a loop LP#1. For each of the loops, the controller housing CTL and the disk device housings DISK are connected serially forming loops with cables EC, which are called ENC cables, connecting the housings.
FIG. 2 is an explanatory diagram showing an actual state of connection between disk device housings. In an example of this figure, two ENC units exist in one disk device housing DISK. PATHs 0 and 1 on a lower disk device housing OUT side and PATHs 0 and 1 on an upper disk device housing IN side are connected by ENC cables EC. In this example, in order to prevent misconnection of the PATHs 0 and 1, connectors are colored in unique colors (milky white and yellow). White circles in the figure indicate milky white and black circles indicate yellow. In addition, colored tags or the like are also attached to connector terminals to prevent misconnection in the same manner. In such a method, costs for attaching tags to connector cables and coloring the connector cables are incurred.
In a disk array device, the number of disk device housings tends to increase according to a demand for increased capacity or the like. In addition, it is attempted to increase the number of disk devices, which are accessible in parallel, and to improve a failure resistance property. As a result, it is attempted to perform connection of fiber channels, for example, by increasing the number of loops so as to form four loops (hereinafter referred to as “four loops”) or adopting a dual path which provides plural controllers to make it possible to access the disk device housings from both directions. Due to these tendencies, that is, the increase in the number of loops and the dual path, the connection of cables in the disk array device tends to be complicated and easily causes misconnection. When misconnection occurs, the disk array device does not operate normally due to a cause such as inconsistency in a combination of disk devices constituting an FC-AL loop, which results in adverse effects such as deletion of stored data by mistake.
As a method of controlling the misconnection, as illustrated in FIG. 2, it is possible to adopt a method of color-coding cables and also coloring connectors of disk device housings and a controller housing to make it easy to recognize locations to which the cables of the respective colors are connected. However, this method has a disadvantage in that the method can only cope with a standardized connection method considered in advance and a disadvantage in that, when a connection method is complicated, the color-coding includes a large number of colors, and excess costs and labor are required for preparation of cables and the like.