Data Robotics Drobo FS Handbuch Seite 21

The General tab allows you to customize your Drobo FS to suit your
individual needs. Here you can protect your data from two hard drives
failing, set the time for the hard drives to spin down and also dim the
lights of your Drobo FS.
Dual disk redundancy is a setting that will protect your stored data
against two simultaneous drive failures. When this additional safeguard
is enabled, the amount of usable space is reduced in order to provide
this added protection. To use dual disk protection, you are required to
have at least three hard disks in your Drobo FS and sufficient free disk
space if there is already data on your Drobo FS.
By default, this setting is disabled. To enable it, go to Advanced
Controls -> Tools -> Settings -> General. Dual disk protection can be
enabled or disabled at anytime as long as you meet the minimum
requirements mentioned above. Note that when you switch from single
disk redundancy (default) to dual disk redundancy, your Drobo FS will
perform a relayout of your data. The drive lights will blink green and
yellow during this process. Depending on the amount of data on your
Drobo FS, this could take quite a while to complete. Do not turn the
power off any time the drive lights are blinking green and yellow.
However, you can shut down your computer during this process.
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