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Verify that the "Reassign Restricted to 1 blk" option is set to Disabled.
f
When enabled, the controller will only request a single block to be
reassigned. When disabled, the controller will reassign all blocks in a
failing request. Most disk drives are now configured to auto-reassign, plus
there is some additional safety in reassigning all blocks in the request
instead of just the one reported by the device. However, this leaves the
risk of reassigning blocks with no errors.
g
Ensure that the option for "Write Through Verify" is set to Disabled.
This option enables disk write through verify. During error handling it
turns on Force Unit Access for reads and writes. Force Unit Access is a
SCSI control descriptor bit (CDB). It is not necessary to use this bit in
error recovery because most drives are already configured for
auto-reassign and write-cache disabled.
h
Set the "RAID 5 Algorithm" option to Right Asymmetric (Right Asym).
This setting controls the layout of RAID 5 parity blocks within the
redundancy group. The Right Asymmetric layout puts parity blocks on
the first disk for the first stripe, the second disk for the second stripe, the
third disk for the third stripe, etc.
The Left Symmetric layout puts parity blocks on the last disk for the first
stripe, the second to last disk for the second stripe, the third to last disk
for the third stripe, etc.
Wrapping is dependent on the number of drives in the group. The
following demostrates this, where P denotes a parity block and D denotes
a data block.
Right Asymmetric
P D D D
D P D D
D D P D
D D D P
P D D D
Etc.
7
Press <Esc> to return to the Advanced Functions menu.
8
Use the arrow keys to select Disk Side Parameters and press <Enter>.
Left Symmetric
D D D P
D D P D
D P D D
P D D D
D D D P
Etc.
Configuring the Array
Configuration
45
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