Avago Technologies MegaRAID Fast Path Software - Manual (Page 208)

Page 208 LSI Corporation Confidential | July 2011
MegaRAID SAS Software User Guide Chapter 4: WebBIOS Configuration Utility | WebBIOS Dimmer Switch
4.14.9 New Drives Attached to a
MegaRAID Controller
When you insert a new drive on a MegaRAID system, if the inserted drive does not
contain valid DDF metadata, the drive displays as JBOD. If the drive does contain valid
DDF metadata, its drive state is Unconfigured Good.
A new drive in JBOD drive state is exposed to the host operating system as a
stand-alone drive. Drives in JBOD drive state are not part of the RAID configuration
because they do not have valid DDF records. The operating system can install and run
anything on JBOD drives.
Automatic rebuilds always occur when the drive slot status changes, for example, when
you insert a drive or remove a drive, so that a hot spare can be used. However, a new
drive in JBOD drive state (without a valid DDF record), will not perform an automatic
rebuild.
To start an automatic rebuild on the new JBOD drive, you must change the drive state
from JBOD to Unconfigured Good. (Rebuilds start only on Unconfigured Good drives.)
After you set the drive state to Unconfigured Good, the drive state information always
remains on the drive, and you can use the drive for configuration.
See Section 4.14.3.3, Troubleshooting Information for more information about DDF and
metadata.
4.15 WebBIOS Dimmer Switch This section describes changing the power-save settings using the Dimmer Switch
feature.
The power savings is done by reducing power consumption of drives that are not in use
by spinning down the unconfigured drives, hot spares, and configured drives.