If a disk drive is defective, you can replace it with another available disk (and its slices) on the system as documented in How to Replace a Component in a RAID-5 Volume. Alternatively, you can repair the disk, label it, and run the metareplace command with the -e option to re-enable the disk.
Make sure that you have a current backup of all data and that you have superuser access.
To enable a failed component in a RAID-5 volume, use one of the following methods:
From the Enhanced Storage tool within the Solaris Management Console, open the Volumes node, then open the RAID-5 volume. Choose the Components pane. Then, choose the failed component. Click Enable Component. Follow the onscreen instructions. For more information, see the online help.
Use the following form of the metareplace command:
# metareplace -e volume-name component-name
Specifies to place the failed component into an available state and to perform a resynchronization on the failed component.
Specifies the name of the volume containing the failed component.
Specifies the name of the failed component.
# metareplace -e d20 c2t0d0s2