RAID Level Drawer Loss Protection RequirementsReplicated pair 1 = Physical disk located in enclosure 1, drawer 0, slot 0, and physical disk inenclosure 0, drawer 1, slot 0Replicated pair 2 = Physical disk in enclosure 1, drawer 0, slot 1, and physical disk inenclosure 1, drawer 1, slot 1Replicated pair 3 = Physical disk in enclosure 1, drawer 0, slot 2, and physical disk inenclosure 2, drawer 1, slot 2RAID Level 10 requires a minimum of four physical disks. Make sure that each physical diskin a remotely replicated pair is located in a different drawer.RAID Level 0 You cannot achieve drawer loss protection because the RAID Level 0 disk group does nothave redundancy.NOTE: If you create a disk group using the Automatic physical disk selection method, MD Storage Managerattempts to choose physical disks that provide drawer loss protection. If you create a disk group by using theManual physical disk selection method, you must use the criteria that are specified in the previous table.If a disk group already has a Degraded status due to a failed physical disk when a drawer fails, drawer loss protectiondoes not protect the disk group. The data on the virtual disks becomes inaccessible.Host-To-Virtual Disk MappingAfter you create virtual disks, you must map them to the host(s) connected to the array.The following are the 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.• Each host has its own LUN address space. MD Storage Manager permits the same LUN to be used by differenthosts or host groups to access virtual disks in a storage array.• All operating system do not have the same number of LUNs available.• You can define the mappings on the Host Mappings tab in the AMW. See Using The Host Mappings Tab.Creating Host-To-Virtual Disk MappingsGuidelines to define the mappings:• An access virtual disk mapping is not required for an out-of-band storage array. If your storage array ismanaged using an out-of-band connection, and an access virtual disk mapping is assigned to the Default Group,an access virtual disk mapping is assigned to every host created from the Default Group.• Most hosts have 256 LUNs mapped per storage partition. The LUN numbering is from 0 through 255. If youroperating system restricts LUNs to 127, and you try to map a virtual disk to a LUN that is greater than or equal to127, the host cannot access it.• An initial mapping of the host group or host must be created using the Storage Partitioning Wizard beforedefining additional mappings. See Storage Partitioning.To create host to virtual disk mappings:1. In the AMW, select the Host Mappings tab.2. In the object tree, select:– Default Group76
