Issue:
Netscaler ADC 12.1 does not save the configuration. When clicked on the save icon in the browser, it prompts whether you want to save running configuration. Nothing happens when you click yes. From the putty session, when you run “save config” command, it outputs “ERROR:”. No error message is displayed.
Solution:
Login to your netscaler through putty and check the free space of /flash directory. Run df -h command on the shell prompt to find the free space. If the free space in flash is less than 70%, you have to delete some files in it.
You will find files for multiple netscaler software release versions in /flash directory. Leave the one with your current netscaler version and delete other gz files. Ensure that the files present in this location are the ones applicable to the current version of the NetScaler software on your appliance. For example, if you are on Netscaler 12.1 60.19 version, in /flash directory, remove older netscaler version gz files. These files will be with the naming convention, ns-12.1-48.13.gz or ns-12.1-51.19.gz etc… Remove these files. But dont delete ns-12.1-60.19.gz file as it is the current version in this example.
Note: Remove only the older versions of the kernel. The /flash directory should contain the files that the current version or build of NetScaler software release is using and the kernel.gz file. Do not remove these files from the /flash directory.
Source: https://support.citrix.com/article/CTX133587
Check the free space of /flash directory again. If it is less than 70%, save the configuration. It should save the configuration without any issues.
Space issue on /var folder could be one of the issue if you are not able to login to the Netscaler GUI.
Clear space on /var and /flash:
To clear /var directory:
https://docs.citrix.com/en-us/citrix-adc/current-release/system/troubleshooting-citrix-adc/how-to-free-space-on-var-directory.html
/var/nstrace - This directory contains trace files.This is the most common reason for HDD being filled on the Citrix ADC appliance. This is due to an nstrace being left running for indefinite amount of time. All traces that are not of interest can and should be deleted. To stop an nstrace, go back to the CLI and issue stop nstrace command.
/var/log - This directory contains system specific log files.
/var/nslog - This directory contains Citrix ADC log files.
/var/tmp/support - This directory contains technical support files, also known as, support bundles. All files not of interest should be deleted.
/var/core - Core dumps are stored in this directory. There will be directories within this directory and they will be labeled with numbers starting with 1. These files can be quite large in size. Clear all files unless the core dumps are recent and investigation is required.
/var/crash - Crash files, such as process crashes are stored in this directory. Clear all files unless the crashes are recent and investigation is required.
/var/nsinstall - Firmware is placed in this directory when upgrading. Clear all files, except the firmware that is currently being used.
To clear /flash directory:
https://support.citrix.com/article/CTX133587/how-to-free-space-in-the-flash-directory-in-a-netscaler-appliance
