Users Guide

controller connector. You must have a good knowledge of RAID levels and hardware, to use the Advanced Wizard. If you want
the wizard to choose a recommended virtual disk configuration for you, select the Express Wizard option.
Before creating a virtual disk, you should be familiar with the information in Considerations Before Creating Virtual Disks. You
may also want to review Choosing RAID Levels And Concatenation.
NOTE: This task is not supported on PERC hardware controllers running in HBA mode.
To create a virtual disk using the Create Virtual Disk Advanced Wizard:
1. On the left-hand side of the Server Administrator page, expand Storage.
2. Click on the <PERC Controller>.
3. Click on Virtual Disks.
The Virtual Disk(s) on Controller <Controller Name> page is displayed.
4. Click Go to the Create Virtual Disk Wizard.
The Create Virtual Disk Wizard (Step 1) <Controller Name> page is displayed.
5. Select the Advanced Wizard option.
6. To make sure that only encrypted physical disks are used to create the virtual disk, select Yes from the Create Encrypted
Virtual Disk drop-down list.
The RAID levels are available for selection based on the number of encrypted physical disks.
If you select No, the RAID levels are available based on the total number of physical disks present on the system.
7. Select the required RAID level from the drop-down list.
● Depending on the controller, Concatenated enables you to combine the storage capacity of several disks or to create
a virtual disk using a single physical disk. For more information on the number of supported physical disks supported by
Concatenated, see Number Of Physical Disks Per Virtual Disk. Using Concatenated does not provide data redundancy
or affect the read/write performance.
● Select RAID 0 for striping. This selection groups n disks together as a large virtual disk with a total capacity of n disks.
Data is alternately stored in the disks so that they are evenly distributed. Data redundancy is not available in this mode.
Read/write performance is enhanced.
● Select RAID 1 for mirroring disks. This selection groups two disks as one virtual disk with the capacity of a single disk.
The data is replicated on both disks. When a disk fails, the virtual disk continues to function. This feature provides
data redundancy and good read performance, but slightly slower write performance. The system must have at least two
physical disks to use RAID 1.
● Select RAID 5 for striping with distributed parity. This selection groups n disks together as one large virtual disk with
a capacity of (n-1) disks. When a disk fails, the virtual disk continues to function. This feature provides better data
redundancy and read performance, but slower write performance. The system must have at least three physical disks to
use RAID 5.
● Select RAID 6 for striping with additional distributed parity. This selection groups n disks as one large virtual disk with
a capacity of (n- 2) disks. The virtual disk remains functional with up to two disk failures. RAID 6 provides better read
performance, but slower write performance. The system must have at least four physical disks to use RAID 6.
● Select RAID 10 for striping over mirror sets. This selection groups n disks together as one large virtual disk with a
capacity of (n/2) disks. Data is striped across the replicated mirrored pair disks. When a disk fails, the virtual disk
continues to function. The data is read from the surviving mirrored pair disk. This feature provides the best failure
protection and read/write performance. The system must have at least four physical disks to use RAID 10. For PERC
controllers with firmware version 6 and later, RAID 10 also allows you to create a single span virtual disk with 22 or 26
physical drives.
● Intelligent Mirroring — Automatically calculates the span composition based on the physical disks you select.
Spans are not displayed on this page. Select Continue to view the span grouping on the Summary page. Click Exit
Wizard to cancel the virtual disk creation.
Storage Management calculates the optimum span composition as follows:
○ Determining span calculation:
￭ Calculating the number of disks that can be utilized from the selected disks.
￭ Maximizing the number of spans to increase the I/O performance
○ Determining the mirror for the physical disks: The mirror is determined in a way that ensures maximum redundancy.
The algorithm also tries to match a physical disk for its mirror, to a disk that is almost the same size. However,
Intelligent Mirroring gives priority to size over redundancy.
The algorithm determines the candidate mirror in the following order:
￭ Across connectors at the same level of enclosure and same size.
￭ Across connectors in the enclosure that are not at the same level but of same size.
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Virtual Disks