Glossary

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: 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:
• SCSI
• SAS
• SATA
9. Select the Media Type.
The available options are:
• HDD
• SSD
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