Config_File Environment Variable; Controlling Environment Variables - Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual

Chapter 3 Configuring the Switch for the First Time

CONFIG_FILE Environment Variable

For class A flash file systems, the CONFIG_FILE environment variable specifies the file system and
filename of the configuration file to use for initialization (startup). Valid file systems can include
nvram:, disk0:, and sup-bootflash:.
For detailed file management configuration information, refer to the Cisco IOS Configuration
Fundamentals Configuration Guide at this URL:
http://www.cisco.com/en/US/docs/ios/12_2/configfun/configuration/guide/ffun_c.html
After you save the CONFIG_FILE environment variable to your startup configuration, the switch checks
the variable upon startup to determine the location and filename of the configuration file to use for
initialization.
The switch uses the NVRAM configuration during initialization when the CONFIG_FILE environment
variable does not exist or when it is null (such as at first-time startup). If the switch detects a problem
with NVRAM or a checksum error, the switch enters setup mode. See the
the setup Command" section on page 3-2

Controlling Environment Variables

Although the ROM monitor controls environment variables, you can create, modify, or view them with
certain commands. To create or modify the BOOT, BOOTLDR, and CONFIG_FILE environment
variables, use the boot system, boot bootldr, and boot config global configuration commands.
Refer to the "Specify the Startup System Image in the Configuration File" section in the "Loading and
Maintaining System Images and Microcode" chapter of the Configuration Fundamentals Configuration
Guide for details on setting the BOOT environment variable. Refer to the "Specify the Startup
Configuration File" section in the "Modifying, Downloading, and Maintaining Configuration Files"
chapter of the Configuration Fundamentals Configuration Guide for details on setting the
CONFIG_FILE variable.
Note •
•
You can view the contents of the BOOT, BOOTLDR, and the CONFIG_FILE environment variables
using the show bootvar command. This command displays the settings for these variables as they exist
in the startup configuration as well as in the running configuration if a running configuration setting
differs from a startup configuration setting.
This example shows how to check the BOOT, BOOTLDR, and the CONFIG_FILE environment
variables:
Router# show bootvar
BOOT variable = disk0:c6sup22-jsv-mz.121-5c.EX.bin,1;
OL-11439-03
When you use the boot system, boot bootldr, and boot config global configuration commands, you
affect only the running configuration. You must save the environment variable settings to your
startup configuration to place the information under ROM monitor control and for the environment
variables to function as expected. Enter the copy system:running-config nvram:startup-config
command to save the environment variables from your running configuration to your startup
configuration.
Cisco IOS software supports the boot bootldr global configuration command and the ROM monitor
supports the BOOTLDR environment variable, but because Release 12.2ZY does not require use of
a bootloader image, there are no Release 12.2ZY bootloader images.
Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY
Modifying the Supervisor Engine Startup Configuration
for more information on the setup command facility.
"Using the Setup Facility or
3-25