A SAS expander module literally expands the number of end devices that you can connect together with existing RAID enclosure having CD-ROM size slot. Expander devices, typically embedded into an expander module to connect system backplane, support large configurations of SAS end devices, including SAS RAID adapters, SAS and SATA disk drives.
With expander devices, you can build large and complex storage topologies. Areca presents its ultra-high performance and high reliability SAS expander module in a cost-effective, enterprise-class enclosure. It support 4 SFF-8087 internal connector for customer to connect to the backplane with SFF-8087 connector. Areca SAS RAID adapters can typically support up to 128 end devices using ARC-8020 expander box and can communicate with both SAS and SATA devices. Areca SAS external RAID controllers can typically support up to 122 end devices using ARC-8020 expander box and can communicate with both SAS and SATA devices. In the backplane solution, SAS/SATA drives are directly connected to SAS system backplane. The system backplane is attached to the SAS RAID controller through an expander module. The number of SAS/SATA drives is limited to the number of slots available on the backplane. Areca SAS expander module supports daisy chain expansion to the next expander module. The Areca SAS RAID controller/SAS RAID adapter can support daisy-chain up to 8 enclosures. The following example figure shows how to connect the external Min SAS cable from Areca SAS RAID controller/SAS RAID adapter that has external connectors to the ARC-8020 expander enclosures.
Expander Architecture
Single expander box
Field-upgradeable firmware in flash ROM
External Interface
One 4x wide-port SAS connectors for host connection
Two 4x wide-port SAS connectors for expander module (JBOD) daisy chain
Drive Interface
Up to 12/16 SAS or SATA II drives per expander module
Up to 3Gb/s per port
Monitors/Indicators
LCD Control Panel for setup, alarm mute and configuration
System status indication through LCD, LED (Link status and Activity) and alarm buzzer
Enclosure management (Protocols SES2 over SAS ports) ready
Management
In-band SAS port
Out-of-band RS232 serial port
CLI through RS232 serial port
Mechanical
Dimension 148(W)x 43(H) x 220(D) mm
I/O Interface
- 1 x (2 x 4) header I2C Port for LCD and button connector
- 1 x (RJ11) serial port connector
- 3 x SFF-8088 for External Host and JBOD Interface
