Configuring Switch Boot Optimization

 

This chapter describes how to configure the Switch Boot Optimization feature for Cisco Industrial Ethernet 2000U Series (IE 2000U) and Connected Grid Switches, hereafter referred to as switch .

This chapter includes the following sections:

Information About Switch Boot Optimization

The normal switch boot process involves a memory test, file system check (FSCK), and power-on self-test (POST). For details about the normal boot process, see the “Boot Process” section.

The boot fast command in global configuration mode minimizes switch boot time by disabling these tests.

If the system crashes when boot fast is enabled, reload sequences occur immediately if your switch is set up to automatically bring up the system by using information in the BOOT environment variable. Otherwise, these reload sequences occur after you enter the manual boot command in bootloader configuration mode.

First Reload

The switch disables the boot fast feature and displays the following warning message:

“Saving the crash information to flash.

Reloading with boot fast feature disabled...”

After the system message appears, the system saves the crash information and automatically resets itself for the next reload cycle.

Second Reload

The boot loader performs its normal full memory test and FSCK check with LED status progress. If the memory and FSCK tests are successful, the system performs additional POST tests and the results are displayed on the console.

After the system comes up successfully, the boot fast feature is reenabled.

Prerequisites

Review the “Information About Switch Boot Optimization” section and “Guidelines and Limitations” section.

Guidelines and Limitations

Caution The system requires the memory test, file system check, and POST to function properly. Enabling switch boot optimization might lead to uncertain system behavior.

Default Settings

By default, boot fast is disabled.

Configuring Switch Boot Optimization

To enable the switch boot optimization feature, enter the following global configuration command:

boot fast

To disable the switch boot optimization feature, enter the following command:

no boot fast

Verifying Configuration

 

Command
Purpose

show boot

Displays information about the switch boot optimization configuration.

Configuration Example

This example shows how to enable, disable, and verify the switch boot optimization configuration:

Switch#conf t
Switch(config)#boot fast
Switch(config)#end
Switch#sh boot
Boot optimization : enabled

 

Switch#conf t
Switch(config)#no boot fast
Switch(config)#end
Switch#sh boot
Boot optimization : disabled
 

Feature History

Platform
First Supported Release

IE 2000U

Cisco IOS Release 15.0(2)EH

CGS 2520

Cisco IOS Release 15.0(2)ED

Ethernet Switch Module (ESM) for CGR 2010

Cisco IOS Release 15.0(2)ED