Various Functions; Raid Functions - Panasonic LB-DH7 Series Operator's Manual

Operations

Various Functions

RAID functions

The unit provides RAID functions for the purpose of improving the reliability and availability.
The fault tolerance for the protection of data is different when writing and reading. RAID levels for each write and
read are listed in the following table.
≥ With this unit, the RAID configuration of each 3.6 TB magazine consists of top and bottom sides of 6 discs (12
sides in total). The RAID configuration of each 1.2 TB magazine consists of 12 discs (12 layers). The 12 layers
that make up the RAID in each magazine is called a "RAID configuration unit".
≥ RAID 5 or 6 for write fault tolerance can be set from the application. In the factory default settings, the write
operation is enabled when the number of drive failure*
For more information about the settings, refer to the user manual for the application.
≥ The maximum transfer rate and the RAID configuration unit capacity for writing are different depending on the
RAID level settings. For the maximum transfer rate and capacity for each RAID level, refer to "Specifications"
( 84).
Number of
drive failure = 1
Fault tolerance in
Number of
write
drive failure = 2
performance
Number of drive
failure S 3
Number of
drive failure = 1
Fault tolerance in
Number of
read
drive failure = 2
performance
Number of drive
failure S 3
The number of writing/reading sides in drive systems that cannot perform reading/writing due to such reasons as
*1
drive failures* 4 , damaged media inside magazines, the lack of space available for management information, and
access to low redundancy areas.
*2 The number of writable drive failures can be set to 0 or 1 in the application.
*3 The number of writable drive failures can be set to 0, 1 or 2 in the application.
It is not possible to write/read data to/from two sides of 3.6 TB magazines in the event of a drive failure.
*4
Note
In order to improve reliability and availability, RAID 5 or 6 is recommended.
1 is 0 for RAID 5, the number of drive failure is 1 for RAID 6.
RAID Level
RAID 0
Writable*
Warning report
No write/Error report
No read/Error report
54
RAID 5
/
2
Writable*
Warning report
Readable/Warning report
RAID 6
/
3