Browse Prior Art Database

Using the Same Printed Circuit Board To Serve As RAID Controller And Simple Switch Card In Disk Expansion Drawer

IP.com Disclosure Number: IPCOM000130349D
Original Publication Date: 2005-Oct-21
Included in the Prior Art Database: 2005-Oct-21
Document File: 4 page(s) / 878K

Publishing Venue

IBM

Abstract

Storage disk drive enclosures generally require dual Controller cards. The Controller card can be a RAID Controller or a simple Switch Controller which personalizes the enclosure to be a RAIDed storage enclosure or a simple SBOD storage enclosure, respectively. Generally the two Controller card types are two different designs, that is, two different part numbers. An improvement is to design a single card that can be selectively populated to perform either the RAID Controller function or the Switch function. Such a design is described as follows.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 57% of the total text.

Page 1 of 4

Using the Same Printed Circuit Board To Serve As RAID Controller And Simple Switch Card In Disk Expansion Drawer

A Controller card is designed to include RAID functionality and SBOD (Switched Bunch of Disk) functionality. Such a design allows it to be used in a RAIDed Storage enclosure as well as in an SBOD enclosure by selectively populating the appropriate functions. The following figures illustrate components of a Dual RAID Controller Storage Subsystem.

Figure 1 shows a RAID Controller card with Host ports (HBA function), Device ports (DA function) and associated Expansion ports for cascading external SBOD enclosures. This design is a superset implementation which can be easily reduced in functionality, enabling the configurations in Figures 2 & 3. There are four Host ports and two sets of Device ports, shown as Loop 0 and Loop 1. This design implements a Fibre Channel Switch which further provides for inter RAID Controller connectivity, as well as, attachment to internal disk drives and a downstream port, Loop 0, for expansion to downstream SBOD enclosures.

Figure 2 illustrates a variation of Figure 1 which provides a cost reduced option whereby half of the Host ports are removed along with half of the DA ports, thus eliminating half of the expansion ports. It should be noted that a common microcode base can be used for both designs.

Figure 3 illustrates yet another variation which removes the bulk of the functionality (RAID Controller). The remaining function is the Fibre Channel Switch which is reconfigured to provide dual upstream ports for connectivity to a RAID Controller (e.g. Figure 1 or Figure 2) and dual downstream ports for attachment to additional SBODs.

As described above, such a Controller card design proivdes many benefits such as a single card design and resultant reduced development cost.

1

Page 2 of 4

Figure 1

Dual RAID Controllers

( 8 x 8 )

Host Ports Expansion Ports

HA Function DA Function Server Function SBOD Function

Host ports

Host ports

RAID Controller A

RAID Controller B

QDR

HBA

HBA

QDR

QDR

HBA

HBA

QDR

SDRAM

 PPC 750GX

SDRAM

 PPC 750GX

 PPC 750GX

IOC

IOC

Comp

Flash

 PPC 750GX

Flash

Enet

Flash

Comp

Flash

Enet

 PPC 750FX

 PCI Bridge

 PCI Bridge

 PPC 750FX

SDRAM

bridge

IOC

IOC

Bridge

SDRAM

SDRAM

SDRAM

Flash

NVRM

Flash

NVRM

DA

DA

DA

DA

SES

SES

FC Switch

FC Switch

FC Switch

FC Sw...