Dynamically upgradeable disk array chassis and method for dynamically upgrading a data storage system utilizing a selectively switchable shunt

A dynamically upgradeable disk array chassis comprising:

• a plurality of ports within said chassis that make connection with a plurality of data storage devices;
• a serial bus, interconnecting said plurality of data storage devices, for carrying high frequency data signals;
• an environmental monitor connected to said plurality of data storage devices to detect a status of a plurality of conditions within said disk array chassis;
• a communication path connected to said environmental monitor for carrying low frequency data signals;
• a connector accessible outside said chassis to allow communication therethrough with a low frequency communication path and a high frequency serial bus from a new disk array chassis;
• a shunt, connected to said serial bus and having a normal state in which said serial bus is disconnected from said connector and a switched state in which said serial bus is in communication, through said connector, with the high frequency serial bus from the new disk array chassis;
• and
• wherein said environmental monitor communicates by low frequency signals through said communication path with the new disk array chassis and afterwards causes said shunt to switch to the switched state.

A dynamically upgradeable disk array chassis comprising:

• a plurality of ports within said chassis that make connection with a plurality of data storage devices;
• a serial bus for interconnecting said plurality of data storage devices, said serial bus including a first bus for carrying high frequency data signals in one direction and a second bus for carrying the high frequency data signals in a second direction;
• a shunt connected to the first bus and the second bus and having a normal bypass state in which the first bus is connected to the second bus across said shunt and a switched state in which each of the first bus and the second bus is connected to a separate output;
• an environmental monitor connected to said shunt to control the state of said shunt;
• a communication path connected to said environmental monitor for carrying low frequency data signals;
• a diplexer connected to said communication path and to the separate outputs of said shunt for combining the high frequency data signals and the low frequency data signals in the one direction and for separating the high frequency data signals from the low frequency data signals in the second direction;
• and
• a connector, connected to said diplexer, accessible outside said chassis to make data communication connection with a low frequency communication path and a high frequency serial bus from a new disk array chassis, wherein said environmental monitor communicates with low frequency signals through said communication path with the new disk array chassis before switching said shunt to the switched state to connect said serial bus to the high frequency serial bus on the new disk array chassis.

A method for dynamically upgrading a data storage system comprising the steps of:

• providing a new disk array chassis having a plurality of data storage devices interconnected by a high frequency data bus, an environmental monitor connected to a low frequency communication path and a diplexer for combining high frequency signals from the high frequency data bus with low frequency signals from the low frequency communication path;
• connecting a cable between the diplexer of said new disk array chassis and a connector on said data storage system;
• communicating with said new disk array chassis with low frequency signals through said cable and said communication path;
• and
• switching a shunt in the data storage system to permit the high frequency signals to communicate between said data storage system and said new disk array chassis.

A method for dynamically upgrading a data storage system comprising the steps of:

• providing a new disk array chassis having a plurality of data storage devices connected to a data bus and an environmental monitor connected to a communication path;
• connecting said new disk array chassis to said data storage system;
• communicating between said data storage system and said new disk array through the communication path;
• and
• activating a switch in said data storage system, in response to said step of communicating, to permit signals to be passed between said data storage system and the data bus on said new disk array chassis.