Thanks for the Reply. The Links are really helpful

About my findings:-

The main reason after our analysis is coming out to be the I/O latch and the avg cpu utilisation of the server is 40% and most of the time the SQL server is waiting to read from the disk drive.

Also the Db files are actively/continuously scanned by the Antivirus

So can you suggest what can be done

Also today i have the following error can you help me why this came

Date1/19/2011 12:37:15 PM

LogSQL Agent (Current - 1/19/2011 12:40:00 PM)

Message

[298] SQLServer Error: 121, TCP Provider: The semaphore timeout period has expired. [SQLSTATE 08S01]

Should i go to the network team for the connectivity issue or the storage team to check the storage as it is taking time to read from the SAN Drives.