User`s guide

4-84 Configuring Your Server
The Disk Cache Policy has the following modes. Select a mode suitable for your environment.
Unchanged • The controller uses the default write cache policy of the hard disk drive.
• The default value may not be identical to the factory-set value, therefore, do
not specify this mode.
Enabled • The controller always uses the write cache policy of the hard disk drive.
• Be sure to use an UPS when specifying this mode as disk cache policy.
Disabled • The controller does not use the write cache policy of the hard disk drive.
• This mode can provide the highest data security, however, the writing
performance is lower than the one in Enabled mode.
• It is recommended to use this mode for the sake of data security.
IMPORTANT:
 If "Unchanged" is specified for Disk Cache Policy, the default value may not be identical to the
factory-set value, therefore, do not specify this mode.
 If Enabled is specified for Disk Cache Policy, the controller uses the write cache policy of the
hard disk drive. Accordingly, the data in cache memory of the hard disk drive may be lost if a
power failure occurs.
 Be sure to use an UPS when using the cache memory of the hard disk drive.
You can change parameters when defining a VD except for RAID Level and Stripe Size. On the WebBIOS Top Menu, click
[Virtual Drives] and specify parameters in the "Policies" frame, then click [Change].