We have a Windows Server 2003 enterprise x64. Quad code xeon, 6Go Ram. Running Exchange server 2007 + sql server. About 20 users. This server was running fine for 1 year, but since 1 month it becames extremely slow for 5-10 minutes or not responding 2 ou 3 times a day. SysInternal Proc explorer is running and I noticed : When it runs fine : Process like store.exe, sqlsrvr, edgetransport, svchost consume about 200-2000Mb of memory each (working set) (store.exe uses up to 2Gb when cache is full) I can see about 2-3Gb a total of physical memory used. Suddenly, when it hangs : Total physical memory used decrease from 2-3Gb to 600/700Mb !!! Biggest procces like store.exe which was using 1G mb drops to 20-50Mb Processors are near 0% I/O bytes suddenly grows ... After 5-10 minutes, memory for theses process grows up and arrive to 2Gb of physical memory used and the server runs fine again .... I have a similar server with same applications and no problem.... Any idea ?

You should never install Sql and Exchange on the same server both of them are extremely disk-intensive applications. People who run SQL Server or Exchange are expecting valid real-time performance. They are not the people submitting batch jobs to a mainframe -- where waiting is expected. End-users are generally unwilling to wait for RPC responses from Exchange, or wait for complex queries to complete against SQL Server. This means you should always plan on isolating these applications, or understanding through the use of Perfmon and WMI the end-user experience you are providingme server. Note: Even Microsoft doesnt supports these kind of issues http://www.virmansec.com/blogs/skhairuddin

Yes I know but sql server is only used by one user and I did'nt install a specific sqlserver machine for one user. And I don't understand why this configuration has worked for 1 year without any problem ? Does the overhead caused by sql + exchsrvr can cause this physical memory decrease ? And when this problem occurs I did"nt noticed extensive disk access.... I have the same config (same machine, exchsrvr + sql) wich works fine. the only difference is 8Gb instead of 6Gb RAM ... Do you think it can be the cause?

Hi, Have you got any event log when the server hangs? If so, please let’s know the detail including the event ID. Meanwhile, please temporarily disable all ant-virus software on the server side to check if this issue still exists. On the other hand, you might find a root cause through doing a small memory dump. For more information: How to read the small memory dump files that Windows creates for debugging http://support.microsoft.com/kb/315263 Thanks.

No event log .... But after many search I've found people with EXACTLY same problem.... It's caused by Kaspersky Antivirus updater. When Kaspersky database update starts, the problem also starts many times : physical memory drop to less than 1Gb, server freeze.... when update is finished memory goes up and everything run fine... Now I've disabled Kaspersky updates and all my servers works fine for 1 week.....

Hi Gilles, Having the exact same problem myself. turning off the updates works but not a long term solution. How did you solve the kaspersky updating issue? Thanks Edward