LSI MegaRAID Express 500 - Manual (Page 24)

MegaRAID Express 500 Hardware Guide 10
Hot Spares
A hot spare is an extra, unused disk drive that is part of the disk subsystem. It is usually in
standby mode, ready for service if a drive fails. Hot spares permit you to replace failed
drives without system shutdown or user intervention.
MegaRAID Express 500 implements automatic and transparent rebuilds using hot spare
drives, providing a high degree of fault tolerance and zero downtime. The MegaRAID
Express 500 RAID Management software allows you to specify physical drives as hot
spares. When a hot spare is needed, the MegaRAID Express 500 controller assigns the
hot spare that has a capacity closest to and at least as great as that of the failed drive to
take the place of the failed drive.
Important
Hot spares are employed only in arrays with redundancy, for
example, RAID levels 1, 3, 5, 10, 30, and 50.
A hot spare connected to a specific MegaRAID Express 500
controller can be used only to rebuild a drive that is
connected to the same controller.
Hot Swap
A hot swap is the manual replacement of a defective physical disk unit while the computer
is still running. When a new drive has been installed, you must issue a command to
rebuild the drive.