Dell PowerVault MD3000 - Manual (Page 101)

Maintaining a Storage Array
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Use Service mode when you want to perform an operation, such as replacing a
RAID controller module. Placing a RAID controller module in Service mode
makes it unavailable for I/O operations. Placing a RAID controller module in
Service mode also moves the disk groups from the RAID controller module to
the second RAID controller module without affecting the disk groups’
preferred path. Moving disk groups might significantly reduce performance.
The disk groups are automatically transferred back to the preferred RAID
controller module when it is placed back online.
NOTICE:
A multipath driver is required on all hosts and is the only supported
configuration. If the multipath driver is not installed, the virtual disks will not be
accessible.
Before you place a RAID controller module in Service mode, ensure that a
multipath driver is installed on all hosts using these virtual disks.
To change the operational mode of a RAID controller module, run the
following command:
set controller [(0 | 1)] availability=(online |
offline | serviceMode)
Changing RAID Controller Module Ownership
You can change which RAID controller module owns a virtual disk by using
the set virtualDisk command. The following syntax is the general form of the
command:
set (allVirtualDisks | virtualDisk
[ virtualDiskName ] | virtualDisks [ virtualDiskName1
... virtualDiskNamen ] | virtualDisk < wwid >) owner=
(0 | 1)
Initializing a Physical Disk
NOTICE:
When you initialize a physical disk, all data on the physical disk is lost.
You must initialize a physical disk when you have moved physical disks that
were previously part of a disk group from one storage array to another. If you
do not move the entire set of physical disks, the disk group and virtual disk
information on the physical disks that you move is incomplete. Each physical
disk that you move contains only part of the information defined for the