Section 2.4: Switch File Management

IOS image files and configuration files are normally used in a Catalyst switch. Files can be stored in the

following file systems:

• Network servers: An external system to the switch is linked to the network to enable FTP, TFTP or remote copy program (rcp) file transfer facilities.

• Flash memory: The switch has Nonvolatile memory where files can be stored and are not damaged after a power cycle.

• NVRAM: The NVRAM file system is duplicated in Flash memory on most switches, and consists of switch configuration utilized at bootup.

• RAM: The switch configuration utilized at runtime and modified by configuration commands is stored in volatile memory.

2.4.1: OS Image Files

IOS image files are stored on the switch in flash memory. Many image file can be stored on the switch but only one can be utilized at runtime. The Catalyst 2950 and 3550 has one flash place to store images, known as flash. The other greater modular switches like the Catalyst 4500 can contain many Flash file systems. With the Catalyst 4500 bootflash holds the IOS image and bootstrap image files while cat4000_flash stores the VLAN database file. PCMCIA cards named siotO:, sioti:, sioti:, etc can be used to enable stored files to be switched by replacing the flash card.

IOS image files are named according to the following format:

mmmmm symbolizes the Catalyst switch model eg cat4000,c3550

fffff symbolizes the feature of the image, usually i. Everything identifying a IP feature set is represented next: k for a cryptographic feature set, s for the IP "Plus feature set, j for the enterprise feature set, d for the desktop set and p for service providers.

mm represents the file format.

vvvv symbolizes the IOS version in the following format: vvv-mmm.bbb.

vvv represents the major release,

mmm represents the maintenance release, and

■ bbb represents the build level.

bin indicates that the image file is a binary executable.

2.4.2: Configuration Files

These files contain switch operation and feature configuration commands. The three most used configuration files are listed below:

• startup-config: The startup-config file is stored in the NVRAM file system and is used at initial bootup. Power failures have no effect on this file

• running-config: During runtime, the running-config file holds a replica of the existing conditions of all commands being executed. All commands are lost when a power failure occurs and when a switch is reloaded.

• vlan.dat: As any VLAN initial and modification configurations are made, they are stored in the VLAN database.

2.4.3: More Catalyst Switch Files

• system_env_vars holds system information like the MAC address, model.

• crashinfo holds text information about prior switch failures.

2.4.4: Moving Catalyst Switch Files

With Cisco IOS Software the Flash file system can be operated in the same manner as a UNIX or DOS operating systems. The system can be manipulated and files can be shifted about to and from different locations. The table below shows the locations of Catalyst switch files.

Table 2.5: Catalyst Switch File Locations

File System



Flash memory normally with bootable IOS image files


Flash memory normally with bootable IOS image files


Optional Flash card memory that can store any file type


Normally holds the startup-config file


This RAM location holds the running-config file and the directory of dynamic switch memory locations.


Any switch file type can be stored and recovered from an external TFTP server without any user authentication.


Any switch file type can be stored and recovered from an external FTP server with user authentication.


Any switch file type can be stored and recovered from an external RCP server with user authentication.

Flash memory enables you to locate directories, files and binary executable files. Files can be copied, renamed, and deleted. The default position in exec mode is the root directory, flash:,. The file management commands are listed Table 2.6.

Table 2.6: File Management Commands



dir [flash:[directory]] cd flash:directory cd cd..

copy flash:[filename] tftp


Copy tftp: flash:[ filename]

Displays files in the current Flash directory.

A Change directory to the directory specified

Changes the directory to the Flash directory

Changes the directory one step up

Copies files between Flash memory and a TFTP server

delete flash:filename erase flash:


format flash:

Deletes a file from Flash memory Files in Flash memory are cleared

copy running-config startup-config


Saves the running configuration

Copy running-config tftp:

copy startup-config running-config

Performed at switch bootups and overwrites

the running configuration

copy tftp: startup-config The permanent configuration is overwritten


erase startup-config