Users Guide

have specified a RAID 5, then the controller calculates the maximum virtual disk size based on the disk
space provided by the 12 physical disks, because the 12 physical disks can be included in a RAID 5.
SAS RAID Controllers
When using a SAS controller, the controller calculates the maximum virtual disk size based on the
available disk space provided by the minimum number of physical disks required to create the RAID level
you selected. For example, if you specified a RAID 5, then the controller calculates the maximum virtual
disk size based on three physical disks, because only three physical disks are required to create a RAID 5.
Channel-Redundant Virtual Disks
When creating a virtual disk, it is possible to use disks attached to different channels to implement
channel redundancy. This configuration might be used for disks that reside in enclosures subject to
thermal shutdown.
NOTE: Channel redundancy only applies to controllers that have more than one channel and that
attach to an external disk enclosure.
Related Concepts
Channel Redundancy
Related Tasks
Creating A Channel-Redundant Virtual Disk
Creating Virtual Disks
Does my controller support this feature? See Supported Features.
In order to implement RAID functions, you must create a virtual disk. A virtual disk refers to storage
created by a RAID controller from one or more physical disks. Although a virtual disk may be created
from several physical disks, it is seen by the operating system as a single disk.
Before creating a virtual disk, you should be familiar with the information in Considerations Before
Creating Virtual Disks.
Storage Management provides wizards to help you create a virtual disk:
• The Create Virtual Disk Express Wizard calculates an appropriate virtual disk layout based on the
available space and controller considerations. Using this wizard, you can quickly create a virtual disk
using recommended selections.
• The Create Virtual Disk Advanced Wizard allows you to specify the read, write, and cache policy for
the virtual disk. You can also select the physical disks and the controller connector to be used. You
need a good knowledge of RAID levels and hardware to use the advanced wizard.
Related Concepts
What is RAID?
Deleting A Virtual Disk
Channel Redundancy
Reconfiguring Or Migrating Virtual Disks
Physical Disk Or Physical Device Properties
Physical Disk Or Physical Device Tasks
Create Virtual Disk Advanced Wizard
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