Administrator Guide

Changing RAID controller ownership of the virtual disk
If the host has a single data-path to the MD storage array, the virtual disk must be owned by the RAID controller to which the host is
connected. You must configure this storage array before you start I/O operations and after the virtual disk is created. You can change the
RAID controller module ownership of a standard virtual disk or a snapshot repository virtual disk. You cannot directly change the RAID
controller module ownership of a snapshot virtual disk because the snapshot virtual disk inherits the RAID controller module owner of its
associated source virtual disk. Changing the RAID controller module ownership of a virtual disk changes the preferred RAID controller
module ownership of the virtual disk.
During a virtual disk copy, the same RAID controller module must own both the source virtual disk and the target virtual disk. Sometimes
both virtual disks do not have the same preferred RAID controller module when the virtual disk copy starts. Therefore, the ownership of
the target virtual disk is automatically transferred to the preferred RAID controller module of the source virtual disk. When the virtual disk
copy is completed or is stopped, ownership of the target virtual disk is restored to its preferred RAID controller module. If ownership of the
source virtual disk is changed during the virtual disk copy, ownership of the target virtual disk is also changed. Under certain operating
system environments, it may be necessary to reconfigure the multi-path driver before an I/O path can be used.
To change the ownership of the virtual disk to the connected controller:
1. In the AMW, select the Storage & Copy Services tab and select a virtual disk.
2. From the menu bar, select the appropriate RAID controller module slot in Storage > Virtual Disk > Change > Ownership/
Preferred Path.
3. Click Yes to confirm the selection.
Removing host-to-virtual disk mapping
To remove the host to virtual disk mapping:
1. In the AMW, select the Host Mappings tab.
2. Select a virtual disk under Defined Mappings.
3. Perform one of these actions:
• From the menu bar, select Host Mappings > LUN Mapping > Remove.
• Right-click the virtual disk, and select Remove from the pop-up menu.
4. Click Yes to remove the mapping.
Changing the RAID controller module ownership of a disk
group
You can change the RAID controller module ownership of a disk group. You can also change the RAID controller module ownership of a
standard virtual disk or a snapshot repository virtual disk. You cannot directly change the RAID controller module ownership of a snapshot
virtual disk because the snapshot virtual disk inherits the RAID controller module owner of its associated source virtual disk. Changing the
RAID controller module ownership of a virtual disk changes the preferred RAID controller module ownership of the virtual disk.
During a virtual disk copy, the same RAID controller module must own both the source virtual disk and the target virtual disk. Sometimes
both virtual disks do not have the same preferred RAID controller module when the virtual disk copy starts. Therefore, the ownership of
the target virtual disk is automatically transferred to the preferred RAID controller module of the source virtual disk. When the virtual disk
copy is completed or is stopped, ownership of the target virtual disk is restored to its preferred RAID controller module. If ownership of the
source virtual disk is changed during the virtual disk copy, ownership of the target virtual disk is also changed. Under certain operating
system environments, it may be necessary to reconfigure the multi-path driver before an I/O path can be used.
To change the RAID controller module ownership of a disk group:
1. In the AMW, select the Storage & Copy Services tab and select a disk group.
2. From the menu bar, select Storage > Disk Group > Change > Ownership/Preferred Path.
3. Select the appropriate RAID controller module slot and click Yes to confirm the selection.
CAUTION:
Possible loss of data access—Changing ownership at the disk group level causes every virtual disk in that
disk group to transfer to the other RAID controller module and use the new I/O path. If you do not want to set every
virtual disk to the new path, change ownership at the virtual disk level instead.
The ownership of the disk group is changed. I/O to the disk group is now directed through this I/O path.
NOTE:
The disk group may not use the new I/O path until the multi-path driver reconfigures and recognizes the new
path. This action usually takes less than 5 minutes.
Disk groups, standard virtual disks, and thin virtual disks 77