NEC Disk Array Controller N8103-89 - Manual (Page 119)

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7. Set "RAID Mode," "Stripe Block," " Fast Init" and "Gigabyte Boundary" on [Define
LD Menu]. To change a setting value, move the cursor to the targeting item by
using the arrow keys "↑" and "↓" and press the [Space] key.
Setting item Initial value Available values
RAID Mode
(RAID level) RAID5 RAID0/RAID1/RAID5/RAID10
Stripe Block 64KB/NA 32KB/64KB/128KB/NA(*)
Fast Init OFF ON/OFF
Gigabyte Boundary OFF ON/OFF
Cache Mode AutoSwitch AutoSwitch/WriteBack/WriteThru
*: Depending on the RAID level, the value is specified as "NA" and cannot be changed.
„
[RAID Mode]
Set the RAID level. Select the proper RAID level to be suit to your purpose.
„
[Stripe Block]
Data division unit in striping. The larger the setting value is, the faster the
sequential data read/write it. The use of stripe blocks in 64 KB is recommended.
„
[Fast Init]
Setting [Fast Init] to "ON" allows the master boot record (MBR) to be initialized in
creation of a logical drive (fast initialization function). Set this item to "ON" to
erase the data in HDDs. Also set this item to "ON" to reinstall OS. Without the fast
initialization, OS can be reinstalled but it may take much time to format partitions.
„
[Gigabyte Boundary]
In logical drive setting, truncate the value less than 1 GB in the capacity of each
HDD to round up it in GB. Always set [Gigabyte Boundary] to "OFF."
„
[Cache Mode]
Set the write cache mode of the disk array controller. See the table below for the
specification of each setting value.
Cache Mode Specification
AutoSwitch
(default) When the additional battery is connected and charged enough to
operate the card normally, the operation takes place in the
WriteBack mode. If the battery is not connected, power remains
only a little, or a battery error is detected, the mode is
automatically changed to WriteThru. This enables data to be
protected at power-off. It is recommended to always set the mode
to AutoSwitch.
WriteBack In this asynchronous control mode, data is written to the cache
memory on the card once and the data in the cache memory is
then written to HDDs. The access performance in this mode is
better than that in WriteThru mode. However, data may be lost at
the occurrence of an unforeseen accident such as instantaneous
power-off.
WriteThru In this control mode, data is written to both the cache memory on
the board and HDDs. In general, the access performance in this
mode is inferior to that in the WriteBack mode.