Dell USC, User Manual

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USC and USC-LCE Operations
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• Select the span length from the
Select Span Length
drop-down menu.
The span length value refers to the number of physical disks included in
each span. Span length applies only to RAID 10, RAID 50, and RAID 60.
The
Select Span Length
drop-down menu is active only if the user has
selected RAID-10, RAID-50, or RAID 60.
• Select the physical disks using the check boxes at the bottom of the screen.
Your physical disk selection must meet the requirements of the RAID level
and span length. To select all of the physical disks, click Select All .
Click
Next
after making your selections.
Advanced Wizard Only - Additional Settings
Use the Additional Settings screen to specify cache policies and stripe
element size. You can also assign a hot spare to the virtual disk.
• Specify the size of the virtual disk in the Size box
• Select the stripe element size from the Stripe Element Size drop-down
menu. The stripe element size is the amount of disk space a stripe
consumes on each physical disk in the stripe. The Stripe Element Size
drop-down menu may contain more options than initially displayed on the
screen. Use the up-arrow and down-arrow keys to display all options.
• Select the read policy from the Read Policy drop-down menu.
– Read Ahead — The controller reads sequential sectors of the virtual
disk when seeking data. The Read Ahead policy may improve system
performance if the data is written to sequential sectors of the virtual
disk.
– No Read Ahead — The controller does not use the Read Ahead policy.
The No Read Ahead policy may improve system performance if the
data is random and not written to sequential sectors.
– Adaptive Read Ahead — The controller initiates the Read Ahead
policy only if the most recent read requests accessed sequential sectors
of the disk. If the recent read requests accessed random sectors of the
disk, then the controller uses the No Read Ahead policy.
• Select the write policy from the Write Policy drop-down menu.