To permanently delete the files, use the squeeze EXEC command. The delete command marks the files as 'deleted,' but the files still take up space in Flash memory. 'On Class A Flash file systems, you can delete individual files using the delete EXEC command and later recover these files with the undelete EXEC command.
During deletion of the IOS to make space for the new IOS, notice ' delete' command does not remove the file from flash until I perform the ' squeeze' the flash. While working to test out some configuration with a Cisco 2600, had to upgrade/downgrade it to match the production device.
