Compaq Infortrend manual Making Arrays Available to Hosts, Mapping Partitions to Host ID/LUNs

2.3.3 Making Arrays Available to Hosts

Figure 2 - 7 Mapping Partitions to Host ID/LUNs

Host ID mapping is a process that associates a logical configuration of drives with a host channel ID/LUN. To avail logical partitions on host channel(s), map each partition to a host ID or one of the LUNs under host IDs. Each ID or LUN will appear to the host adapter as one virtual hard drive.

There are alternatives in mapping for different purposes:

1.Mapping a logical configuration to IDs/LUNs on different host channels allows two host computers to access the same array. This method is applicable when the array is shared in a clustering backup.

2.Mapping partitions of an array to IDs/LUNs across separate host channels can distribute workload over multiple data paths.

3.Mapping across separate host channels also helps to make use of all bandwidth in a multi-path configuration. Firmware automatically manages the process when one data path fails and the workload on the failed data path has to be shifted to the existing data paths.

Figure 2 - 8 Mapping Partitions to LUNs under ID

RAID Planning 2-9