You can enable a component when any of the following conditions exist:
Solaris Volume Manager cannot access the physical drive. This problem might occur, for example, due to a power loss, or a loose drive cable. In this case, Solaris Volume Manager puts the components in the “Maintenance” state. You need to make sure that the drive is accessible (restore power, reattach cables, and so on), and then enable the components in the volumes.
You suspect that a physical drive is having transitory problems that are not disk-related. You might be able to fix a component in the “Maintenance” state by simply enabling it. If enabling the component does not fix the problem, then you need to do one of the following:
Physically replace the disk drive and enable the component
Replace the component with another available component on the system
When you physically replace a disk, be sure to partition the disk like the replaced disk to ensure adequate space on each used component.
Always check for state database replicas and hot spares on the disk that is being replaced. Any state database replica in an erred state should be deleted before you replace the disk. Then, after you enable the component, recreate the state database replicas using the same size. You should treat hot spares in the same manner.