Configuration: Disk Groups and Virtual Disks 131
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.
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.
Table 10-2. Criteria for Enclosure Loss Protection
(continued)
RAID Level Criteria for Enclosure Loss Protection
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