Fast Recovery
This function recovers data quickly by relocating data in the failed drive to the other remaining drives when a
drive error is detected.
A RAID level (RAID6-FR) that preserves reserved areas equivalent to hot spares in a RAID group is used.
Figure 9 Fast Recovery
Failed drive
RAID6-FR ((3D+2P) × 2)
RAID6-FR (No redundancy)
: Redundant data for area A
of the failed drive
: Redundant data for area B
of the failed drive
: Fast recovery Hot Spare (FHS)
Failure
RAID6-FR ((3D+2P) × 2 + 1HS)
High Speed Rebuilding
(Creating data and writing to the FHS area simultaneously)
Disconnect
RAID6-FR (Redundant)
A f
ailed drive is disconnected from the
ETERNUS storage system.
Data is created from the redundant data
in normal drives and written to reserved
space (FHS) in RAID6-FR.
Protection (Shield)
The Protection (Shield) function diagnoses temporary drive errors. A drive can continue to be used if it is deter-
mined to be normal. The target drive temporarily changes to diagnosis status when drive errors are detected by
the Disk Drive Patrol function or error notifications.
For a drive that configures a RAID group, data is moved to a hot spare by a rebuild or redundant copy before the
drive is diagnosed.
For a drive that is disconnected from a RAID group, whether the drive has a permanent error or a temporary error
is determined. The drive can be used again if it is determined that the drive has only a temporary error.
The target drives of the Protection (Shield) function are all the drives that are registered in RAID groups or regis-
tered as hot spares. Note that the Protection (Shield) function is not available for unused drives.
3. Basic Functions
Data Protection
32
FUJITSU Storage ETERNUS DX500 S3/DX600 S3 Hybrid Storage Systems
Overview
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