User guide

IMPORTANT: In an environment in which your system
is always subject to load, the transition process may take
a long time and may cause a performance decrement. In
this case, we recommend you specify “OFF” for the
Revertible setting 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 a revertible type. (See "3.15 Creating or Deleting Spare Drives" for
details.)
Revertible
2. Occurrence of fault in PD2
A fault occurs in one of the physical drives configuring a disk array. The disk array enters the
degraded state (the logical drives enter the critical state).
3. The Hot spare rebuild is done by using PD4 to create a logical drive configured with PD1,
PD3 and PD4.
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