Drobo DroboElite, User Manual, Page: 13 / 178

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Warning! Please note that when adding hard drives to DroboPro/DroboElite,
any pre-existing data on those drives will be erased.
Choosing capacity
The number and capacity of drives determine how much usable
protected storage your DroboPro or DroboElite provides. Take the
guesswork out by using our Capacity Calculator
(
www.drobo.com/calculator ), a web-based tool which determines the
usable protected capacity, based on any combination of drives. To
calculate the approximate capacity yourself, omit the largest drive and
then add-up the capacity of the remaining drives. If you plan to use dual
disk redundancy, omit the largest two drives. For example (largest
drives are crossed out):
Single Disk (Default) Redundancy
# of Drives Drive Capacities Usable Protected Capacity
3 250GB + 250BG + 250GB = 500GB
4 250GB + 250BG + 250GB + 500GB = 750GB
4 750GB + 250BG + 250GB + 500GB = 1000GB
Dual Disk Redundancy
# of
Drives Drive Capacities Usable Protected
Capacity
4 250GB + 250BG + 250GB + 500GB = 500GB
5 750GB + 500BG + 500GB + 500GB + 250GB = 1250GB
6 750GB + 1TB + 500GB + 500GB + 500GB = 1500GB
A note about drive capacity
Some years ago, computer manufacturers and hard drive manufacturers
started using different systems for measuring capacity. The net result is
that not all of a drive’s rated capacity is available to your computer. For
example, a 750GB drive will have approximately 700GB worth of
capacity. This discrepancy has nothing to do with Drobo storage devices.
Keeping your product up-to-date
During your initial setup, Drobo Dashboard asks you if you want to
check for updates automatically. We highly recommend you select the
“Yes” option to assure optimal performance of your DroboPro or
DroboElite. This feature enables you to keep both Drobo Dashboard and
your product’s firmware current. Subsequently, you will receive a notice