Hard drives in Sun SPARC Enterprise T5120 and T5220 servers are capable of being removed and installed while the server is running. This feature, referred to as being hot-pluggable, depends on how the hard drives are configured.
Note - Sun SPARC Enterprise T5120 and T5220 servers support both traditional, disk-based storage devices and flash SSDs, diskless storage devices based on solid-state memory. The terms “hard drive” and “HDD” (hard disk drive) are used in a generic sense to refer to both types of internal storage devices.
To hot-plug a drive, you must first take it offline. This prevent applications from accessing it and removes software links to it.
There are two conditions that will prevent a drive from being hot-plugged:
The hard drive contains the sole image of the operating system -- that is, the operating system is not mirrored on another drive.
The hard drive cannot be logically isolated from the server’s online operations.
If either of these conditions exist, you must power off the server before replacing a hard drive.