Dell 3 User Manual
Page 178
176
PERC 3 BIOS Configuration Utility
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– CanSpan: Array spanning is enabled for the current logical drive.
The logical drive can occupy space in more than one array.
– NoSpan: Array spanning is disabled for the current logical drive.
The logical drive can occupy space in only one array.
PERC 3 supports spanning for RAID 1 and RAID 5 arrays only. You can
span two or more contiguous RAID 1 logical drives into a RAID 10
array, or two or more contiguous RAID 5 logical drives into a RAID 50
array.
For two arrays to be spanned, they must have the same stripe width
(they must contain the same number of physical drives) and they must
be consecutively numbered. For example, assuming Array 2 contains
four disk drives, it can be spanned only with Array 1 and/or Array 3,
and only if Arrays 1 and 3 also contain four physical drives.
If the two criteria for spanning are met, PERC 3 automatically
activates spanning. If the criteria are not met, the span setting makes
no difference for the current logical drive.
12
Highlight a spanning option and press <Enter>.
13
Set the logical drive size.
14
Move the cursor to Size and press <Enter>.
By default, the logical drive size is set to all available space in the
array(s) associated with the current logical drive, accounting for the
span setting.
15
Open the Advanced Menu to set the remaining options.
16
Set the Stripe Size.
Stripe size specifies the size of the segment written to each disk in a
RAID 1 or 5 logical drive. You can set the stripe size to 2 KB, 4 KB, 8
KB, 16 KB, 32 KB, 64 KB, or 128 KB. A larger stripe size produces
higher read performance, especially if your computer does mostly
sequential reads. However, if your computer does random read
requests more often, choose a smaller stripe size. The default is 64 KB.
17
Set the Write Policy.
Write Policy specifies the cache write policy. You can set the write
policy to Write-back or Write-through: