Dell MD3200, MD3220 owner manual Host-to-Virtual Disk Mapping, 116

Table 9-2. Criteria for Enclosure Loss Protection (continued)

RAID Level Criteria for Enclosure Loss Protection

RAID level 1 Ensure that each physical disk in a mirrored pair is located in a different expansion enclosure. This enables you to have more than two physical disks in the disk group within the same expansion enclosure.

For example, if you are creating a six physical disk, disk group (three- mirrored pairs), you could achieve enclosure loss protection with only two expansion enclosures by specifying that the physical disk in each mirrored pair are located in separate expansion enclosures. This example shows this concept:

•Mirror pair 1—Physical disk in enclosure 1 slot 1 and physical disk in enclosure 2 slot 1.

•Mirror pair 2—Physical disk in enclosure 1 slot 2and physical disk in enclosure 2 slot 2.

•Mirror pair 3—Physical disk in enclosure 1 slot 3and physical disk in enclosure 2 slot 3.

Because a RAID level 1 disk group requires a minimum of two physical disks, enclosure loss protections cannot be achieved if your storage array has less than two expansion enclosures.

RAID level 0 RAID level 0 does not have consistency, you cannot achieve enclosure loss protection.

Host-to-Virtual Disk Mapping

After you create virtual disks, you must map them to the host(s) connected to the array.

Guidelines to configure host-to-virtual disk mapping:

•Each virtual disk in the storage array can be mapped to only one host or host group.

•Host-to-virtual disk mappings are shared between controllers in the storage array.

•A unique LUN must be used by a host group or host to access a virtual disk.

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Configuration: Disk Groups and Virtual Disks