NEC EXPRESS5800 User Manual

 

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The rebuild feature can recover redundancy if a single HDD is defected in RAIL level 1, 10 or 
5. 

During rebuild, data read/write is enabled. However, the redundancy is lost until the rebuild 
operation is completed. 

If an HDD is defected, logical drives are entered into the critical state, of which you are notified.   

IMPORTANT: Note that load is applied to the system to 
decrease its processing rate during rebuild. 

 

If a redundant logical drive is degraded, hot spare rebuild is done under where all the following 
conditions match. 

Spare drives are set. 

Spare drives of either of the following types are required: 

• 

Spare drives set to global 

• 

Spare drives dedicated for logical drive entered into degraded 
state 

Spare drives have capacity set 
properly. 

Spare drives should have capacities equal to or larger than 
those of defected physical drives. 

 

 

When the above conditions are met, host spare rebuild is started automatically. (The physical 
drives that is not configured to any disk arrays cannot be used as spare drives.) 

 

Hot swap rebuild is done when the following conditions are met. 

Auto Rebuild is enabled. 

Enable Auto Rebuild should be checked in the Settings screen 
appearing in the Background Activities tab of subsystem ST 
EX4650EL. See the description of the Background Activities tab in 
"3.5.1 Subsystem (ST EX4650EL) icon" for details. 

A defected physical drive is 
replaced with a new HDD on 
the same slot. 

The new HDD should have a capacity equal to or larger than that 
of the defected physical drive. 

 

If the above conditions are met, hot swap rebuild is started automatically.