To safely remove a hard drive, you must:
Prevent any applications from accessing the drive.
Remove the logical software links.
Drives cannot be hot-plugged if:
The drive provides the operating system, and the operating system is not mirrored on another drive.
The drive cannot be logically isolated from the online operations of the server module.
If your drive falls into these conditions, you must shut down the Oracle Solaris OS before you replace the drive.