RAID Subsystem Expansion
Original Publication Date: 2001-Sep-01
Included in the Prior Art Database: 2003-Jun-20
Disclosed is a circuit implementation to allow storage expansion in a RAID subsystem. Typical components of a RAID subsystem include RAID Controller, power supply(ies), disk drives, I/O card(s), fan(s), and backplane. Each additional component adds cost to the subsystem. This circuit implementation is a means to reduce components required in the subsystem. The RAID Controller has external connections to the disk drive busses via the backplane and host connections via connectors on the RAID assembly. By routing the drive bus connection through the RAID assembly (from the backplane to an external connector), expansion to additional storage boxes known as JBODs (Just a Bunch Of Disks) can be done through the RAID Assembly eliminating the need for an I/O card. Then, identical enclosures can be used for both the RAID subsystem and the storage (JBOD) subsystem by simply inserting a RAID Assembly or I/O assembly into the expansion slot. The storage expansion from the RAID system is done through the RAID assembly and connection to and from the storage system is done through the I/O assembly. In a fibre system, there are typically 2 storage busses on the backplane. The system also incorporates 2 expansion slots so there is not a single point of failure. For duplex (2 controller) operations, a single bus is routed through each RAID assembly so that there is no single point of failure to the storage and the I/O assembly is not required.