We have encountered a very weird error after installing ISPConfig 18.104.22.168. Basically it causes Apache/mod_php to create thousands of open files (actually FIFO pipes), and they are staying open until the system runs out. REFERENCE On our production servers running ISPConfig 22.214.171.124, lsof |wc-l shows 2-5000 open files, and if traffic is declining this number decreases fast, no problem there. On newly installed servers with 126.96.36.199, there is no problem. ERROR Ou our newly installed server with 188.8.131.52, after clicking through the web interface a couple of times (and maybe some PHPMyAdmin pages as well, to increase load a bit), lsof shows a growth to 10-20000 open files in a minute, and they never close. After a couple of minutes, the web server slows to a halt and PHP pages do not load anymore. ENVIRONMENT We have tested this on several different (freshly installed) servers: - Ubuntu 8.04 with perfect server setup (OpenVZ) Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.7 - Debian 5 with perfect server setup (OpenVZ) Apache/2.2.9 (Debian) PHP/5.2.6-1 The only difference is that on Debian, restarting apache actually closes the open files, while on Ubuntu they are kept open even then.