Managing Configuration Files Larger than NVRAM

To maintain a configuration file that exceeds the size of NVRAM (512 KB), you must compress or relocate the configuration file. This section provides an example of each approach. For more information, refer to the Cisco IOS Configuration Fundamentals Configuration Guide.

Compressing the Configuration File

Use the service compress-configglobal configuration command to compress the configuration file for storage in NVRAM. A compressed file can take several minutes longer to load than an uncompressed file.

To compress configuration files, use the following commands, beginning in global configuration mode:

Step 1 Specify that the configuration file is to be compressed.

Router(config)# service compress-config

Step 2 Exit global configuration mode.

Router(config)# end

Step 3 Use one of the copy commands to copy the new configuration, for example:

Router# copy running-config startup-config

Building configuration...

Compressing configuration from 129648 bytes to 11077 bytes [OK]

To cancel the compression feature, use the no service compress-configcommand.

Note If you try to load a configuration that is more than three times larger than the NVRAM size, the following error message appears: [buffer overflow—file-size/buffer-sizebytes].

Relocating the Configuration to a Flash Disk

To run the startup configuration off a Flash disk, use the following commands beginning in privileged EXEC mode:

Step 1 Copy the current startup configuration to a new location. In the following example, the configuration file is copied from a TFTP server to a Flash disk in slot 0:

Router# copy tftp://172.16.2.15/example-config disk0:router-config

Step 2 Enter global configuration mode.

Router# configure terminal

Router(config)#

Step 3 The buffer that holds the configuration file is usually the size of NVRAM (512 KB). Larger configurations need larger buffers. Change the size of the buffer that holds the configuration commands.

Router(config)# boot buffersize 1024000

Step 4 Specify that the startup configuration file is located in Flash memory by setting the CONFIG_FILE variable. In the following example, the system is told that the boot configuration file is in slot 0 and the filename is router-config:

Router(config)# boot config disk0:router-config

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Cisco Systems 10008 quick start Managing Configuration Files Larger than Nvram, Compressing the Configuration File