I have a DELL Poweredge 1950 rack server.On this server my SQL Server database is hosted. Since last month it has become very noisy and irritating. I checked my CPU usage but it is normal.Is it due to SQL server 2008 ? Also what factors should I consider to reduce this noise? Update : Today I came to know that noise started because of a particular application which was running since last month.
1U servers are always noisy. If it sounds like a small jet engine in there, that's because you've got fans that are so small, they need to spin at ~10,000 RPM to move enough air to cool the server when it's under load. The fan speed is variable, so at startup or full load they kick up to maximum RPMs, and should be automatically adjust downwards when less cooling is needed. You can monitor the fan speed with (among other things) the Dell OpenManage software.
I would personally, use that (or whatever hardware monitoring system you use) to check on the temperatures inside the server (to see if they warrant increased fan speed to cool), as well as make sure the probes and sensors for the fans are operating properly, and within normal voltage ranges.
But, to some extent, this is normal, especially given the age of the 1950 PowerEdge platform. If the noise is really a concern, try cleaning and oiling the fans, or replacing the old ones in there with new ones. Airflow restrictions could also be causing sub-optimal cooling and requiring higher fan speeds, as could an increase in ambient temperatures, or increased air temp near the fan intakes. General age and contaminant build-up can also be an issue, so it might be worthwhile to pull out the server, and take a can of compressed air to blow out any dust and grime, which can negatively impact cooling and heat-dissipation within the server.
If none of that helps, and you have reason to be concerned, you might want to consider the possibility that the server's starting to give up the ghost - hardware's running hot, out of normal voltage ranges, and is showing the first signs of an impending hardware failure.
The main noise will be coming from the fans - servers have many different ones on the CPUs, Memory, Disks, Case etc. In some cases these will dynamically adjust their speeds based on the temperature they detect but in many they just run at what ever speed they are set to either manually or in the BIOS.
I'm not sure whether the 1950 has the ability to automatically adjust their speed. If they are, it will generally be a setting in the BIOS.