Dell DC, 3, User Manual

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Configuring PERC 3 93
Arranging Arrays
You must arrange the arrays to provide additional organization for the drive
array. You must arrange arrays so that you can create system drives that can
function as boot devices.
You can sequentially arrange arrays with an identical number of drives so
that the drives in the group are spanned. Spanned drives can be treated as
one large drive. Data can be striped across multiple arrays as one logical
drive.
You can create spanned drives using the PERC 3 BIOS Configuration
Utility.
Creating Hot Spares
Any drive that is present, formatted, and initialized but is not included in
an array or logical drive can be designated as a hot spare.
You can designate drives as hot spares using the PERC 3 BIOS
Configuration Utility.
Creating Logical Drives
Logical drives are arrays or spanned arrays that are presented to the
operating system. You must create one or more logical drives. The logical
drive capacity must include all of the disk space in an array. If an array with
drives with mixed sizes, the smallest common size is used and larger disk
drives are truncated. The logical drive capacity can also be larger than an
array by using spanning. PERC 3 supports up to 40 logical drives.
Configuration Strategies
The most important factors in RAID array configuration are:
• Drive capacity
• Drive availability (fault tolerance)
• Drive performance
You cannot configure a logical drive that optimizes all three factors, but it is
easy to choose a logical drive configuration that maximizes one factor at the
expense of the other two.