Compaq AA-RHGWC-TE manual Introduction

•Using a RAID array controller in transparent failover mode allows the use of hardware RAID to mirror the disks. However, without a second SCSI bus, second Memory Channel, and redundant networks, this configuration is still not a NSPOF cluster (Section 1.5.4).

•By using an HSZ70, HSZ80, or HSG80 with multiple-bus failover enabled you can use two shared SCSI buses to access the storage. Hardware RAID is used to mirror the root (/), /usr, and /var file systems, and the member system boot disks, data disks, and quorum disk (if used).

A second Memory Channel, redundant networks, and redundant power must also be installed to achieve a NSPOF cluster (Section 1.5.5).

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The figures in this section are generic drawings and do not show shared SCSI bus termination, cable names, and so forth.

1.5.1Two-Node Clusters Using an UltraSCSI BA356 Storage Shelf and Minimum Disk Configurations

This section takes the generic illustrations of our cluster example one step further by depicting the required storage in storage shelves. The storage shelves could be BA350, BA356 (non-UltraSCSI), or UltraSCSI BA356s. The BA350 is the oldest model, and can only respond to SCSI IDs 0-6. The non-Ultra BA356 can respond to SCSI IDs 0-6 or 8-14 (see Section 3.2). The UltraSCSI BA356 also responds to SCSI IDs 0-6 or 8-14, but also can operate at UltraSCSI speeds (see Section 3.2).

Figure 1–3 shows a TruCluster Server configuration using an UltraSCSI BA356 storage unit. The DS-BA35X-DA personality module used in the UltraSCSI BA356 storage unit is a differential-to-single-ended signal converter, and therefore accepts differential inputs.

Introduction 1–7