Reference Guide

Recovering from a Failed Start on the S4820T System

A system that does not start correctly might be attempting to boot from a corrupted Dell Networking OS

image or from a mis-specified location.

In this case, you can restart the system and interrupt the boot process to point the system to another

boot location. Use the setenv command, as described in the following steps. For details about the

setenv command, its supporting commands, and other commands that can help recover from a failed

start, the u-Boot chapter in the Dell Networking OS Command Line Reference Guide.

1. Power-cycle the chassis (pull the power cord and reinsert it).

2. Hit any key to abort the boot process. You enter uBoot immediately, the => prompt indicates

success.

(during bootup)

press any key

3. Assign the new location to the Dell Networking OS image it uses when the system reloads.

uBoot mode

setenv [primary_image f10boot location | secondary_image f10boot location |

default_image f10boot location]

4. Assign an IP address to the Management Ethernet interface.

uBoot mode

setenv ipaddre address

5. Assign an IP address as the default gateway for the system.

uBoot mode

setenv gatewayip address

6. Reload the system.

uBoot mode

reset

Restoring the Factory Default Settings

Restoring the factory-default settings deletes the existing NVRAM settings, startup configuration, and all

configured settings such as, stacking or fanout.

S4820TMXL Switch

To restore the factory default settings, use the restore factory-defaults stack-unit {0-5 |

all} {clear-all | nvram} command in EXEC Privilege mode.

CAUTION: There is no undo for this command.

Important Points to Remember

• When you restore all the units in a stack, these units are placed in standalone mode.

Management