NEC Express 320Lc-R - Manual (Page 80)

4-36 Windows Setup
6. If the inserted hard disk is not a dynamic disk, right-click the disk and perform “Convert to
Dynamic Disk”.
7. Right-click the dynamic disk volume for creating mirror and click [Add Mirror…].
8. Select the newly inserted HDD in the window which appears, and click [Add Mirror] to
continue with the mirroring process.
IMPORTANT:
When you click [Add Mirror…], the [Logical Disk Manager] dialog box
will appear, but this is not an error. Click [OK].
If you restart the system while creating mirror, mirroring will not be
completed. Do not reboot the system until the mirroring process is
completed.
TIPS: Creating mirror takes about 37 minutes for 18GB hard disks.