Transition - NEC EXPRESS5800 User Manual

3.12 Transition

At the occurrence of a fault, logical drives may be degraded and recovered by hot spare rebuild.
This results in separation of the configured slot positions of the logical drives. However,
creating spare drives of revertible type previously (see "3.15 Creating or Deleting Spare
Drives") allows logical drives to be returned to the original successive slot positions.
IMPORTANT: In the environment in which your system
is always subject to load, the process of transition may
take a long time and the performance may cause
performance decrement. In this case, the setting of
Revertible is recommended to be OFF when creating a
spare drive.
The transition is useful in the following situations.
<Example of auto transition>
1. Original state (RAID5)
Create spare drives of revertible type. (See "3.15 Creating or Deleting Spare Drives" for
details.)
2. Occurrence of fault in PD2
A fault occurs in a physical drive among those configuring a disk array. The disk array is
entered into the degraded state (logical drives are entered into the critical state).
Revertible
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