## Changing the write-cache m ode on a hard disk drive

Use this action to enable or disable the write-cache mode setting of a hard disk drive. The write-cache mode determines if the hard disk drive stores data before or after sending a confirmation to the controller.

1. Click a ready drive from the Main Tree.
2. Click Actions --> Change write-cache mode to write back/write through.
3. Click Yes.

If you set the write-cache mode to write back, the controller sends data to the hard disk drive for storage. Subsequently, the hard disk drive sends a confirmation to the controller before actually storing the data. Doing so increases performance, but also contains an element of risk. If there is a power failure, the data currently in the drive cache is lost.

> Attention: It is possible to lose data if a power outage occurs while using the write-back mode. Consider carefully whether to enable write-back mode on a hard disk drive. Depending on how you use the system, write-back mode might be undesirable.

If you set write-cache mode to write through, the controller sends data to the hard disk drive for storage. Subsequently, the hard disk drive stores the data; then, sends a confirmation to the controller. Using write-through mode can decrease performance, but has no risk of losing data.