You use the metareplace command when you replace or swap an existing component with a different component that is available and not in use on the system.
You can use this command when any of the following conditions exist:
A disk drive has problems, and you do not have a replacement drive, but you do have available components elsewhere on the system.
You might want to use this strategy if a replacement is absolutely necessary but you do not want to shut down the system.
You are seeing soft errors.
Physical disks might report soft errors even though Solaris Volume Manager shows the mirror/submirror or RAID 5 volume in the “Okay” state. Replacing the component in question with another available component enables you to perform preventative maintenance and potentially prevent hard errors from occurring.
You want to do performance tuning.
For example, by using the performance monitoring feature available from the Enhanced Storage tool within the Solaris Management Console, you see that a particular component in a RAID 5 volume is experiencing a high load average, even though it is in the “Okay” state. To balance the load on the volume, you can replace that component with a component from a disk that is less utilized. You can perform this type of replacement online without interrupting service to the volume.