User manual

FastTrak TX4310 User Manual
104
Spare Drives are automatically added to an array once a disk member of the
array has been detected as failed. To restore fault tolerance as quickly as
possible, the FastTrak Controller performs an automatic data rebuild on the spare
drive in the background without the need to restart the system. At a later time, the
failed drive can be physically removed and a new drive added in its place to
function as the spare drive.
Cache Settings
Sets the FastTrak controller’s cache mode for each logical drive. The choices are
WriteBack and WriteThru (write through). A write-back cache holds data after
an I/O operation and tells the controller the data has been written. The data is
written as soon as the disk drive is no longer busy.
This action increases availability of the logical drive. If the power fails before the
data is written to the disk drive, the data will be lost.
The alternative is a write-through cache policy, which reports that the data has
been written to the disk only when it actually has.
Logical Drive Expansion
To expand a logical drive is to increase the number of disk drives.
The FastTrak TX4310 RAID Controller card supports logical drive expansion.
However, you must use the WebPAM software to access this function.
See “Logical Drive Migration and Expansion” on page 75.