Users Guide

● 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.
￭ Across enclosures connected to the same connector and to a disk of the same size.
￭ Within the enclosure with a physical disk of acceptable size difference.
￭ Across connectors at the same level of enclosure and of acceptable size difference.
￭ Across connectors in the enclosure that are not at the same level of the enclosure but with a physical disk of
acceptable size difference.
If the size difference is not acceptable, the disk is not mirrored and hence dropped from the span. The number of spans
and disks in the span is recalculated.
NOTE:
It is recommended that you use Intelligent Mirroring to create RAID 10 across enclosures for simple and
optimum configuration.
NOTE: After a hard disk being used to create RAID 10 VD with Intelligent Mirroring enabled, the same disk cannot
be used to create another RAID 10 VD with Intelligent Mirroring enabled.
NOTE: To view the redundancy across enclosures achieved through Intelligent Mirroring, click the virtual disk and
view the physical disk IDs in each span, which are from alternate enclosures.
● Select RAID 50 to implement striping across more than one span of physical disks. RAID 50 groups n*s disks as one
large virtual disk with a capacity of s*(n-1) disks, where s is the number of spans and n is the number of disks within
each span.
● Select RAID 60 to implement striping across more than one RAID 6 span. RAID 60 groups n*s disks as one large virtual
disk with a capacity of s*(n-2) disks, where s is the number of spans and n is the number of disks within each span. RAID
60 provides increased data protection and better read performance, but slower write performance.'
8. Select the Bus Protocol.
The possible options are:
● SAS
● SATA
● PCIe
9. Select the Media Type.
The available options are:
● HDD
● SSD
For more information on Bus Protocol and Media Type, see Virtual Disk Properties And Tasks.
10. Click Continue.
The Create Virtual Disk Advanced Wizard (Step 2 of 3) — <Controller Name> page is displayed with the connectors
and physical disks available.
Virtual Disks
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