3Ware 9550SXU-12 User Guide - Page 164

Maintaining Units You can still read and write data from a degraded unit, but the unit will not be fault tolerant until it is rebuilt using the Rebuild feature. When a RAID unit becomes degraded, it is marked as such, and the drive(s) that failed are marked as Not In Use in the 3BM screens and Degraded in the 3DM pages. If supported by your enclosure, the LED for failed drives may turn red. You should replace the failed drive and rebuild the unit as soon as it is convenient to do so. The unit will not be fault tolerant until it has been rebuilt. Rebuilding can occur automatically, depending on your settings. For more information, see "Rebuilding Units" on page 167. About Inoperable Units Units become inoperable when there are no longer enough drives in the unit for it to function. For example, a RAID 5 unit created from four drives becomes degraded if one drive fails or is removed, but becomes inoperable if two drives fail or are removed. A RAID 6 unit created from five drives becomes degraded if one or two drives is removed, but becomes inoperable if three drives fail or are removed. Data on an inoperable unit cannot be accessed unless the missing drives are reconnected. If you have data on a unit that is currently "inoperable," contact technical support. Locating a Drive by Blinking Its LED If you use a supported enclosure with enclosure services, you may be able to easily identify the drives in a unit, or locate an individual drive, by causing the LEDs associated with the drives to blink. You can issue the command to blink the LED through 3DM or 3BM. (For details about what the different LED patterns on the enclosure may mean, see "Enclosure Drive LED Status Indicators" on page 149.) To blink the LED for a drive through 3DM 1 Do one of the following: • Choose Information > Drive Information from the main menu in 3DM. On the Drive Information page, identify the drive you want to physically locate. 152 3ware SAS/SATA RAID Software User Guide, Version 9.5.1