Handling RAID Member Disk Showing PD Missing

A disk in the RAID array displays as red PD Missing, as shown below

Click on Drives on the right side, as shown below

Select the disk shown in black in the figure, check the Properties option, and click GO

Select the Make Unconf Good option, click GO, as shown below

Select Replace Missing PD, click GO, as shown below

Select Make Online, click GO, as shown below

Select YES, as shown below

The disk status is now normal