Table of Contents
Advertisement
operations put the array into the Degraded state. When the missing member disk drives
are reintroduced, the array returns to the Good state.
Degraded State
A RAID-10 array is in the Degraded state when one or more member disk drives are
missing or deconfigured, and a write operation has occurred. Read and write operations
can be performed on the array. The missing member disk drives are deconfigured so
that they are permanently excluded from the array. If they become available again, they
can be introduced only as new members.
A RAID-10 array is in the Degraded state also if the secondary half of the array
operates while the primary half is deconfigured. Under this condition, the secondary half
holds information about the members of the primary half to track recovery.
Rebuilding State
A RAID-10 array is in the Rebuilding state when a rebuilding operation is running on
one or more member disk drives. Read and write operations can be performed on the
array.
When an array is created, it enters the Rebuilding state to synchronize the member disk
drives. When the rebuilding operation is complete, the array returns to the Good State.
If the medium-error table fills during a rebuilding operation, the array remains in the
Rebuilding state until space becomes available in the table.
Offline State
A RAID-10 array can be in the Offline state for any of the following reasons:
v No NVRAM is available to operate the array.
v The array is split across SSA loops.
v All these three conditions exist:
– In the secondary half of the array, the member disk drive that contains the
configuration sector is present.
– In the primary half of the array, no members that hold configuration sectors are
present.
– The Split Array Resolution flag is not set.
v All these three conditions exist:
– In the primary half of the array, disk drive members that hold configuration sectors
are present.
– In the secondary half of the array, the member disk drive that contains the
configuration sector is not present.
– The Split Array Resolution flag is set.
v In the primary and secondary halves of the array, member disk drives that hold
configuration sectors are present, and the Split Array Resolution flag is set on the
secondary half. The array, however, was not initialized correctly.
v Two failures in a configuration update (configuration sectors, fence sector, label
sector, medium-error table, or unsync table).
Chapter 3. RAID Functions and Array States
37
Advertisement
Table of Contents
