11.3. Hot-Plug SCSI Drives

All HP drives that are mounted on a hot-plug drive carrier can be removed and installed during system operation.

The SCSI ID of hot-pluggable drives is assigned automatically. The bay position of the drive automatically determines the SCSI ID. The IDs are hard-coded on the backplane board. The SCSI ID is assigned to the drive bay and not to the drive itself; so when you remove a hot-pluggable drive, it will lose its SCSI ID.

The SCSI controller, not the drives, controls HP hot-pluggable drive LEDs. If you use a third-party controller, you will have no support for the LEDs.

11.3.1 Hot-Plug Drive Support

Several of the advantages provided by Smart Array controllers require hot-pluggable SCSI drives. Without hot-pluggable drives, the following operations cannot be completed with the drive online:

• Replacement of a failed drive in a fault-tolerant array

• Addition of drives and arrays

• Expansion of arrays

Although HP supports non-hot-pluggable drives on all of its array controllers, they are not recommended. One of the primary advantages of array controllers is the ability to recover fully from a drive failure without taking the server offline. This capability requires the use of hot-pluggable drives in conjunction with an array controller.

11.3.2 Hot-Pluggable Drive LEDs

The HP Smart Array controller firmware is enhanced so that when the controller detects that an attached hot-pluggable hard drive has entered a degraded status, the amber LED on the hard drive flashes. This enhancement allows easier detection and replacement of the affected physical hard drive, especially when reported by a system management utility such as Insight Manager 7. The affected hot-pluggable hard drive remains online and displays the LED combinations listed in the following table.

Figure 11-1 shows the various meanings of the LED indicators.

Figure 11-1. Drive LED indicators.

The following table explains LED indicators.

Status	Condition
Online	On
Drive Access	On, off, or blinking
Drive Failure	Blinking amber

Note

This feature is not supported in a non-fault-tolerant RAID 0 configuration. The controller must be in a fault-tolerant configuration: RAID 1, RAID 1+0, RAID 5, or RAID advanced data guarding (ADG).

11.3.3 Replacing Hot-Pluggable SCSI Drives

Built-in hot-plug drive support enables you to insert or remove drives in fault-tolerant configurations with the system running.

If the hard drive LED activity light is on or flashing while the online light is also on, it indicates that the drive is online and being accessed. If a predictive failure alert is received when the online and drive access lights are on simultaneously (provided that the array is configured for fault tolerance and all other drives in the array are online), you can replace the drive online. Remove the drive only if the replacement drive is immediately available.

A drive can be hot-plugged during normal activity. When a drive is hot-plugged, the subsystem will no longer be fault tolerant until the removed drive is replaced and the rebuild operation is completed.

Warning

If another drive fails when replacing a hot-pluggable disk drive, the entire array will be lost.