Recovering From an Operating System Failure

•Does the NAS system boot completely?

Connect a keyboard, mouse, and monitor to the NAS system, and observe the boot process.

•Are the LEDs for all hard drives in the NAS system lit?

If the LEDs for the hard drives are not all lit, you may have a failed hard drive. See "Software-RAID NAS System Hard-Drive Failures."

External Storage Configuration NAS System Hard-Drive Failures

Your external storage configuration NAS system has a mirror of the operating system on the internal software-RAID hard drives and external storage for data volumes, which allows you to recover in most cases. Depending on which drive fails, use one of the procedures in Table 6-3 to recover from a hard-drive failure.

Table 6-3. External Storage NAS System Hard-Drive Recovery Procedures

Hard Drive That Failed	Necessary Action

Internal hard drive 0 or1	Replace the failed hard drive. See "Replacing External Storage Configuration NAS System Internal Hard
	Drives ."

If both internal hard drives fail	Replace the failed hard drives, and then follow the procedures in "Reinstalling the Operating System."
One or more external storage hard drives	Replace the failed hard drives, and then follow the procedures in your external storage system's
fail	documentation.

Replacing External Storage Configuration NAS System Internal Hard Drives

This section provides the procedures for replacing internal hard drives 0 or 1.

Replacing Hard Drives

1.Remove the front bezel.

2.Remove the failed hard drive from the NAS system.

See your Installation and Troubleshooting Guide for information about removing and replacing drives.

3.If you are replacing hard drive 0 and the system is not powered on, move the hard drive in slot 1 to slot 0, and then insert the new hard drive into slot 1 and proceed to step 5. Otherwise, proceed to step 4.

This procedure allows the system to boot during step 6.

4.Insert a new hard drive in the same location.

5.Replace the front bezel.

6.Turn on the system, if it is not turned on already.

NOTE: The NAS system automatically starts rebuilding the operating system volume. The rebuild procedure may take several hours.

NOTE: The NAS system takes approximately 5 minutes to boot completely.

NOTE: If the volume does not start building, you do not have a drive that is the same size or larger than the failed drive, you did not have the drive in the system when the system booted, or you were not using a RAID 1 volume. Use Array Manager to repair or reconfigure your volumes. See "Disk and Volume Management."