Laptop User Manual

Configuration: Disk Groups and Virtual Disks 127
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 host
as part of the MDSM install process.
8 Restart the host applications.
Changing 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 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 might 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 Logical tab and select a virtual disk.
2 Select Virtual Disk  Change  Ownership/Preferred Path .
3 Select the appropriate RAID controller module slot and click Yes to
confirm the selection.
book.book Page 127 Wednesday, June 8, 2011 5:01 PM