Product manual

Chapter 7: Technology Background
283
Spare Drives
A spare drive is a physical drive that you designate to automatically replace the
failed physical drive in a disk array. See “Creating a Spare Drive Manually” on
page 142.
The general recommendation is to:
• Provide at least one spare drive for every 16 physical drives in the RAID
system
• Configure the spares as global revertible spare drives
Options
There are several options you can specify for a spare drive:
• System Options
• Revertible – Returns to its spare drive assignment after you replace the
failed physical drive in the disk array and run the Transition function.
• Media Patrol – By default, Media Patrol runs on spare drives unless
you disable it.
•Spare Type
• Global – Can be used by any disk array
• Dedicated – Can be used only by the assigned disk array
• Media Type (type of physical drive)
• Hard Disk Drive (HDD)
• Solid State Drive (SSD)
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