Dell PowerVault 725N (Rackmount NAS Appliance) - Manual (Page 119)

You might need the software-RAID NAS system to boot from the recovery operating system mirror so that you can perform a file restore on the main operating
system mirror or access the data on the data partition and back it up to tape.
To boot from the recovery drive, perform the following steps:
1. Shut down the NAS system.
2. Remove the front bezel.
3. Swap hard drives 0 and 2 with each other.
See your Installation and Troubleshooting Guide for information about swapping drives.
4. Swap hard drives 1 and 3 with each other.
5. Replace the bezel.
6. Turn on the NAS system.
The NAS system boots from the operating system on hard drives 0 and 1.
7. Log in to the NAS Manager.
See " Logging in to the NAS Manager " in the "NAS Manager" section of this guide.
8. Back up your data and then reinstall the operating system. See " Reinstalling the Operating System " in this section of the guide for the operating
system reinstallation procedures.
Introduction to Hardware-RAID NAS System Recovery and Restoration Procedures
This section provides instructions on how to recover the hardware-RAID NAS system if the operating system or a hard drive fails. Additionally, this section
provides information for possible solutions that do not require restoring the operating system or hard drives.
Because your NAS system is designed to have redundancy, it can recover from certain hardware and software failures. In some situations, it can recover
automatically, and in others, you must have administrator privileges and manually intervene to recover the NAS system.
Use the following methods in the order listed to restore your hardware-RAID NAS system:
1. Check all of the items in " Troubleshooting Hardware-RAID NAS Systems " in this section of the guide.
2. Check the procedures in " Hardware-RAID NAS System Hard-Drive Failures " in this section of the guide.
Troubleshooting Hardware-RAID NAS Systems
This section provides checks and solutions to try before you reinstall your operating system or replace a hard drive. Some of the checks require you to observe
the LEDs on the front and back of the NAS system. For more information about the LEDs, see your Installation and Troubleshooting Guide.
l Does the power LED show that the NAS system is turned on?
Ensure that the power cable connected to the NAS system and a power source and that the NAS system is turned on.
NOTE: The recovery operating system mirror is intended as a temporary way to back up your data. After performing the backup, reinstall the operating
system using the procedures in " Reinstalling the Operating System " in this section of the guide.
NOTE: Because the system boots using the recovery image operating system with the Dell default settings, any configuration information is lost.
See " Configuring Your NAS System for the First Time " in the "Initial Configuration" section of this guide.
NOTICE: If your NAS system uses software RAID, see " Introduction to Software-RAID NAS System Recovery and Restoration Procedures " in this section
of the guide. Do not use the following procedures to recover and restore a software-RAID NAS system. For instructions on how to determine if you have
a software-RAID or a hardware-RAID NAS system, see "
Determining if a NAS System Uses Software RAID or Hardware RAID " in the "NAS Manager"
section of this guide.