Users Guide
Related links
Virtual Disk Considerations For PERC S100, S110, S130, And S300 Controllers
Number Of Virtual Disks Per Controller
There are limitations on the number of virtual disks that can be created on the controller. For information about the maximum
number of virtual disks supported by a controller, see the virtual disk specications for the controller in Supported Features.
Calculation For Maximum Virtual Disk Size
The Create Virtual Disk Express Wizard displays the minimum and maximum values for the virtual disk size. This section describes
how the maximum possible size for the virtual disk is calculated based on the controller type. To identify the controller type, see
RAID
Controller Technology: SATA and SAS.
SATA RAID Controllers
When using a SATA RAID controller, the controller calculates the maximum virtual disk size based on your RAID level selection and
the available physical disk space provided by all suitable physical disks attached to the controller. For example, if the controller
contains 12 physical disks with available space and you have specied 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 specied 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 dierent channels to implement channel redundancy. This
conguration 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 links
Channel Redundancy
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.
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