  The DESY Computer Center is the home of O(1000) computers supplying a wide
range of different services Monitoring such a large installation is a
challenge. After a long time running a SNMP based commercial Network Management
System, the evaluation of a new System was started. There are a lot of
different commercial and freeware products on the market, but none of them
fully satisfied all our requirements. After re-valuating our original
requirements we selected NAGIOS as our monitoring and alarming tool. After a
successful test we are in production since autumn 2002 and are extending the
service to fully support a distributed monitoring and alarming.
