The service compress-config is a nice feature from Cisco that mimics the Microsoft NTFS compression. It allows to reduce the size of the startup-file, in some cases to one quarter of the original size.
Configuring the service compress-config command
Configuring the compression feature is easy. Position yourself at the global configuration level and issue the command service compress-config on the Cisco switch:
When you do a write mem, usually the IOS will display a simple message saying that configuration has been saved. However, with service compress-config, this same message becomes the following:
Compressed configuration from … bytes to … bytes[OK]
Here is an example:
One immediate drawback of this command is that write mem and show run take a little much longer to execute than usual. Don’t tell me it’s due to a high resource usage. I tried them on a fresh Catalyst 3650 and they do take a bit of time.
Disabling service compress-config
To disable the compression of the startup-file, simply do a no service compress-config on the global configuration mode.