If you create a Solaris Volume Manager RAID-1 (mirror) or RAID-5 volume in a disk set that is built on top of a soft partition, hot spare devices do not work correctly.
Problems that you might encounter include, but are not limited to, the following:
A hot spare device might not activate.
A hot spare device status might change, indicating the device is broken.
A hot spare device is used, but resynced from the wrong drive.
A hot spare device in use encounters a failure, but the broken status is not reported.
Workaround: Do not use this configuration to create a Solaris Volume Manager RAID-1 or RAID-5 volume in disk sets.