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. However, you do have available components elsewhere on the system.
You might want to use this strategy when a replacement is absolutely necessary, but you do not want to shut down the system.
You see soft errors on the physical disks.
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.
One way that you can evaluate components is by using the performance monitoring feature available from the Enhanced Storage tool within the Solaris Management Console. For example, you might 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.