Dell 3000i manual Cabling the Enclosure, Redundancy vs. Nonredundancy, Direct-Attached Solutions

Cabling the Enclosure

You can connect up to 16 hosts and two expansion enclosures to the storage array.

To plan your configuration, complete the following tasks:

1Evaluate your data storage needs and administrative requirements.

2Determine your hardware capabilities and how you plan to organize your data.

3Calculate your requirements for the availability of your data.

4Determine how you plan to back up your data.

The iSCSI interface provides many versatile host-to-controller configurations. For the purposes of this manual, the most conventional topologies are described. The figures in this chapter are grouped according to the following general categories:

•Direct-attached solutions

•Network-attached (SAN) solutions

Redundancy vs. Nonredundancy

Nonredundant configurations, configurations that provide only a single data path from a host to the RAID enclosure, are recommended only for non-critical data storage. Path failure from a failed or removed cable, a failed NIC, or a failed or removed RAID controller module results in loss of host access to storage on the RAID enclosure.

Redundancy is established by installing separate data paths between the host and the storage array, in which each path is to different RAID controller modules. Redundancy protects the host from losing access to data in the event of path failure, because both RAID controllers can access all the disks in the storage array.

Direct-Attached Solutions

You can cable from the Ethernet ports of your host servers directly to your MD3000i RAID controller iSCSI ports. Direct attachments support single path configurations (for up to four servers) and dual path data configurations (for up to two servers) for both single and dual controller modules.

Single Path Data Configurations

With a single path configuration, a group of heterogeneous clients can be connected to the MD3000i RAID controller through a single physical Ethernet port. Because there is only the single port, there is no redundancy (although each iSCSI portal supports multiple connections). This configuration is supported for both single controller and dual controller modes.

Figure 2-1 and Figure 2-2 show the supported nonredundant cabling configurations to MD3000i RAID controller modules using the single path data configuration. Figure 2-1 shows a single controller array configuration. Figure 2-2 shows how four standalone servers are supported in a dual controller array configuration.

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Hardware Installation