We had a client-server with a disk running out of space and the log /opt/cloudera/security/log/krb5kdc.log was the cause
/opt/cloudera/security/log/krb5kdc.log was 14GB. We moved and compressed it to krb5kdc.log.bak.gz, it is now just 137MB. The krb5kdc service had to be restarted to release the handle to the old log file on the filesystem. Space went down to 23%.
This is not a solution to a problem, but a workaround. The problem is that /opt is on a root filesystem, which is small. The problem will reoccur soon.
I checked /etc/krb5.conf, but it shows a different log directory.