Configuration: Disk Groups and Virtual Disks 131• Right-click the virtual disk, and select Change Mapping from thepop-up menu.3 In Host group or host, select the appropriate host group or host.By default, the drop-down list shows the current host group or the hostassociated with the selected virtual disk.4 In Logical unit number, select the appropriate LUN.The drop down list shows only the currently available LUNs that areassociated with the selected virtual disk.5 Click OK.Stop any host applications associated with this virtual disk, and unmountthe virtual disk, if applicable, from your operating system.6 In the Change Mapping dialog, click Yes to confirm the changes.The mapping is checked for validity and is saved. The Defined Mappingspane is updated to display the new mapping. The Topology pane is alsoupdated to reflect any movement of host groups or hosts.NOTE: If a password is set on the storage array, the Enter Password dialog isdisplayed. Type the current password for the storage array, and click OK.7 If configuring a Linux host, run the rescan_dm_devs utility on the host,and remount the virtual disk if required. This utility is installed on the hostas part of the MDSM install process.8 Restart the host applications.Changing Controller Ownership of the Virtual DiskIf the host has a single data-path to the MD storage array, the virtual diskmust be owned by the controller to which the host is connected. You mustconfigure this storage array before you start I/O operations and after thevirtual disk is created.You can change the RAID controller module ownership of a standard virtualdisk or a snapshot repository virtual disk. You cannot directly change theRAID controller module ownership of a snapshot virtual disk because thesnapshot virtual disk inherits the RAID controller module owner of itsassociated source virtual disk. Changing the RAID controller moduleownership of a virtual disk changes the preferred RAID controller moduleownership of the virtual disk.
