You can obtain the information from " show status " command
System will start automatically purging out old log files when it detects that the system has crossed high watermark threshold value. If it is /common partition, turning off any additional traces should help the system in this scenario.
Also, you can download the old log files via RTMT and select the option to delete them from the server.
the high water mark threshold is 95% after that the cucm will purge the files. If you want the make lower just change this setting. Have a look on the documentation on how the high and low water mark works.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...