Avago Technologies 3ware 9650SE-12ML (Channel) - Manual (Page 244)

3DM 2 Reference
232 3ware SAS/SATA RAID Software User Guide, Version 9.5.1
Rescanning is useful in a variety of maintenance tasks. For example, if you
physically plug in a drive and want the controller to recognize the newly
plugged-in drive, Rescan will find it.
Rescan checks all ports. It checks empty ports for newly plugged-in drives. If
those drives were previously part of a 3ware RAID configuration and they
still have valid DCB (Disk Configuration Block) information on them, the
controller tries to piece them back together into a working unit. If a working
unit can be formed, it will appear in the Unit Maintenance list when the scan
is complete, and the operating system will be notified of the unit. In Linux or
FreeBSD, a device node will be associated with each unit created. In
Windows, the device manager will reflect the changes under the disk drives
icon. This process is known as importing drives.
If new drives do not have any data indicating they were previously part of a
3ware RAID configuration, they will appear in the Available Drives list.
In addition, if there is a unit with the status Inoperable before a rescan (for
example, a RAID 5 unit missing 2 or more drives), and a rescan finds drives
that complete the unit, the inoperable unit will become a valid unit.
Unit Maintenance
The Unit Maintenance section of the page lists all existing units on the current
controller, and displays summary information about them.
The top row shows information about the unit, while subsequent rows show
summary information about each drive in the unit.
Unit Information
Note: If you unplug a drive without first removing it through 3DM, Rescan may not
recognize it as gone unless the drive was in use or until it is required by the system.
Always use the
Remove link to remove a drive before unplugging it.
Warning: Physically removing or adding drives which are not in hot swap bays can
result in a system hang or may even damage the system and the drive.