Dell PowerVault MD3200 Owner's Manual - Page 117

• Each host has its own LUN address space. MDSM permits the same LUN to be used by different hosts or host groups to access virtual disks in a storage array. • Not every operating system has the same number of LUNs available. • You can define the mappings on the Mappings tab in the Array Management Window. See "Using the Mappings Tab" on page 84. Creating Host-to-Virtual Disk Mappings Guidelines to define the mappings: • An access virtual disk mapping is not required for an out-of-band storage array. If your storage array is managed 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. To prevent this action from occurring, remove the access virtual disk mapping from the Default Group. • Most hosts have 256 LUNs mapped per storage partition. The LUN numbering is from 0 through 255. If your operating system restricts LUNs to 127, and you try to map a virtual disk to a LUN that is greater than or equal to 127, the host cannot access it. • An initial mapping of the host group or host must be created using the Storage Partitioning Wizard before defining additional mappings. See "Storage Partitioning" on page 126. To create host to virtual disk mappings: 1 In the AMW, select the Mappings tab. 2 In the Topology pane, select: • Default Group • Undefined mappings node • Individual defined mapping • Host group • Host 3 In the toolbar, select Mappings Define Additional Mapping. The Define Additional Mapping window is displayed. Configuration: Disk Groups and Virtual Disks 117