Hi, I'm not sure if it is the reason but the probability is high: After the security update of the linux kernel, in my case from k_deflt-2.4.18-57 to k_deflt-2.4.18-261, I have two frozen systems. In the first case we are running a program that starts some stored procedures in a Informix Database (IDS 9.30.UC1). After a few minutes there are no more actions possible on that server. You can't find any message in /var/log/messages or online.log. Even recursively started commands like ps or onstat -g ses sid -r 1>protfile does not generate any output. In the second case the similar happened during daily cronjob which builds and loads a database of ca. 8 GB size. My question: Has anybody else problems with these kernel updates related to Informix Dynamic Server. Reinhard.