Avago Technologies MegaRAID SATA 150-4 (523) - Manual (Page 34)

2-12 Introduction to RAID
Copyright © 2003–2006 by LSI Logic Corporation. All rights reserved.
2.4.13.1 Rebuild Rate
The rebuild rate is the percentage of the compute cycles dedicated to
rebuilding failed drives. A rebuild rate of 100 percent means the system
gives priority to rebuilding the failed drives.
The rebuild rate can be configured between 0 and 100 percent. At
0 percent, the rebuild is done only if the system is not doing anything
else. At 100 percent, the rebuild has a higher priority than any other
system activity. LSI recommends not using 0 or 100 percent. The default
rebuild rate is 30 percent.
2.4.13.2 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,
a rebuild occurs automatically if:
•
The newly inserted drive is the same size as or larger than the
failed drive
•
The drive is placed in the same drive bay as the failed drive it
is replacing
The RAID controller can be configured to detect the new disks and
rebuild the contents of the disk drive automatically.
2.4.14 SCSI Physical Drive States
The SCSI Physical drive states are described in Table 2.3 .
Table 2.3 SCSI Physical Drive States
State Description
Online The physical drive is working normally and is a part of a
configured logical drive.
Ready The physical drive is functioning normally but is not part of a
configured logical drive and is not designated as a hot spare.
Hot Spare The physical drive is powered up and ready for use as a spare in
case an online drive fails.
Fail A fault has occurred in the physical drive, placing it out of service.
Rebuild The physical drive is being rebuilt with data from a failed drive.