Hitachi 220H Bios Manual page 87

The following table shows description of menu items in the window.
You need connect the AC cables of the system unit to a UPS, when you
NOTICE
use the RAID controller without cache backup module and set Default
Write to Always Write Back. Otherwise, the data corruption may
result when blackout or momentary loss of power occurs.
If multiple virtual drives reside on the same Drive Group, keep the
same setting for all the virtual drives.
Table 2-12: Virtual Drive menu items
Menu items
Properties
RAID Level
Status
Strip Size
Capacity
1
Parity Size
Policies
Access
Read
Disk Cache
I/O
Disable BGI
Default Write 2
Notes:
1 This item is displayed when the virtual drive is RAID5 or 6.
2 If you use the RAID controller without cache backup module, use this item with the default setting
when installing an OS. Even if the system unit is connected to a UPS, the install may not finish
normally.
Hitachi Compute Rack 210H/220H BIOS Guide
Description
RAID level
Status of the virtual drive
Strip size of the virtual drive
Size of the virtual drive
Parity size of the virtual drive
Access mode
Read policy
Setting the cache installed
in a physical disk
Setting the read-cache operation
Setting the background
initialization
Setting the write cache of the disk
array
MegaRAID WebBIOS
Setting/display value
-
-
-
-
[RW (reading and writing)] /
Read Only (reading only) /
Blocked (access denied)
[Normal (no read ahead)] /
Ahead (always read ahead)
[Disable (cache: not used)] /
[Enable (cache: used) /
No Change (based on the disk setting)
[Direct (cache: not used)] /
Cached (cache: used)
No (background initializing valid) /
[Yes (background initializing invalid)]
● RAID controller with cache backup
module:
Write Through /
Always Write Back /
[Write Back With BBU]
● RAID controller without cache
backup module:
[Write Through] /
[Always Write Back] /
Write Back With BBU
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