Resolution
The NVRAM cannot be increased and is not upgradeable. This insufficient NVRAM issue is normal in switches with large configuration files.
The workaround is to save the configuration file as a text file. To do this, issue the set config mode text command, where there is the option to save the configuration either in bootflash: or in slot0: (PCMCIA Flash card).
Note: When the configuration mode is set to text-configuration, the configuration is not automatically saved, as in binary mode. A write memory command must be issued in order to save the configuration every time a change is made. However, there is an auto-save feature in text-configuration mode.
Refer to article How to automatically save NVRAM configurations in CatOS when the switch is running in different configuration modes (binary or text mode) for details on how to enable the auto-save feature.