An Origin2000 deskside or rackmount chassis and an Onyx2 rackmount module can support up to eight Ultra SCSI boards, resulting in up to 32 SCSI channels. An Onyx2 deskside chassis can have up to three Ultra SCSI boards, for a total of 12 SCSI channels. Figure 2-1 diagrams how the Ultra SCSI board fits into the overall Origin2000/Onyx2 I/O structure.
Cabling for single-ended storage cannot exceed one meter; cabling for differential storage cannot exceed 25 meters.
The Ultra SCSI board supports database, media, and throughput configurations. This chapter discusses:
topologies with CHALLENGE Vault storage
topologies with Origin Vault storage
 | Note: For ease of reading, CHALLENGE is written as Challenge in the balance of this guide. |
Figure 2-2 diagrams a database topology using Challenge Vault storage. Designed to maximize storage capacity, this topology uses serial striping across the disks.
Figure 2-3 diagrams a topology for media installations that offers bandwidth as well as high storage capacity.
Figure 2-4 diagrams a throughput configuration that offers bandwidth and high IOPs.
| Note: Fast-20 SCSI is not available for Challenge Vault storage. |
Figure 2-5 diagrams a topology using single-ended storage. For the differential part of the path, the total differential length of all connections cannot exceed 25 m.
The Origin Vault with six drives fills storage needs in a high-capacity configuration. Figure 2-6 diagrams a database topology using Origin Vault storage.
Figure 2-7 diagrams a throughput configuration that offers bandwidth and high IOPs.
In a high-bandwidth Fast-20 configuration, three Fast-20 drives fully utilize a single Fast-20 bus; additional drives provide no incremental increase in throughput, although they of course provide additional capacity. Four channels on one Ultra SCSI board configured this way fully utilize the PCI bus that these channels are on.