Promise Technology Pegasus3 R4, Product Manual, Page: 196 / 232

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Technology Background Pegasus3 Product Manual
Requirements
The spare drive must:
• Have adequate capacity to replace the largest physical drive in your disk arrays.
• Be the same media type as the physical drives in your disk arrays.
A revertible spare drive requires:
• You to replace the failed physical drive in the disk array
• You to run the Transition function
Transition
Transition is the process of replacing a revertible spare drive that is currently part of a disk array with an
unconfigured physical drive or a non-revertible spare. The revertible spare drive returns to its original
status. In order to run the Transition function, the spare drive must be revertible.
In addition, you must specify an unconfigured physical drive of the same or larger capacity and same
media type as the revertible spare drive.
Running a Transition
The Transition feature enables you to specify “permanent” spare drives for your Pegasus unit.
Transition is the process of replacing a revertible spare drive that is currently part of a disk array with an
unconfigured physical drive or a non- revertible spare. The revertible spare drive returns to its original
status.
Transition happens automatically when the following sequence of events takes place:
• You create a revertible spare drive. See “Creating a Spare Drive Manually” on page 152.
• A physical drive assigned to your disk array fails and the array goes critical or degraded.
• Pegasus automatically rebuilds your array to the revertible spare drive and the array
becomes functional again.
• You replace the failed physical drive with a new physical drive of equal or greater capacity.
• Pegasus automatically transitions (moves) the data from the revertible spare to the new
physical drive.
• The new physical drive becomes part of the array and the revertible spare drive returns to
its original spare status.