Toshiba Magnia 560S - Manual (Page 189)

Logical Drive Menu
Running Power Console Plus
171
Change Read Policy
Click on Read to change the Cache Read Policy. Table 12.8 lists the available options:
Table 12.8 Cache Read Policy Options
Setting Description
Normal The MegaRAID controller does not use read-ahead for the
selected logical drive.
Read Ahead The MegaRAID controller uses read-ahead for the selected
logical drive.
Adaptive Read
Ahead The MegaRAID controller begins using read-ahead if the two
most recent disk accesses occurred in sequential sectors. If all
read requests are random, the algorithm reverts to Normal.
However, all requests are still evaluated for possible sequential
operation. This is the default setting.
Change Write Policy
Click on Write to change the Cache Write Policy. Table 12.9 lists the available options.
Table 12.9 Cache Write Policy Options
Setting Description
Write Back The MegaRAID controller sends a data transfer completion
signal to the host when the controller cache has received all the
data in a transaction. This is the default setting.
Write Thru The MegaRAID controller sends a data transfer completion
signal to the host when the disk array has received all the data in a
transaction. Write-through caching has a data security advantage
over write-back caching. Write-back caching has a performance
advantage over write-through caching.
Virtual Sizing
Click on this option to enable or disable the Virtual Sizing Option. The Enable Virtual
Sizing feature does not take effect until the next reboot.
NOTE: Virtual sizing is not supported in Windows 2000.