We have been working on FMS 10/11 on a Mac Mini for some years without big problems. Performance was becoming low so we decided to move to an IBM Server with virtualized Windows 2008 Server. At the same time we made the update to FMS 12. This was end of Septmber. Since then FMS 12 crashes almost every second day. It does not quit immediately but gets very slow. Some client requests are not answered anymore while others still are (for a short period). Server scripts still seem to be executed normally. Clients who force quit their FM are not disconnected anymore and if they restart, they get two entries in the clients list on the server console. It's possible, to disconnect all clients from the console. But it's not possible anymore to close the databases. They remain in the status 'closing'. After a force quit and reboot, the databases are going to be verified. A couple of minutes before the clients experience the problems the server writes out a *.dmp file. Most of the times there is another *.dmp file from about one hour before.
What are the occasions the server writes a *.dmp?
What might cause this kind of problem?
Any hints are highly appreciated.