Hi All, I am learning iostat command to understand disk I/O statistics. We have 2 Centos 4 servers running where oracle is installed.We installed them 2 weeks ago. @ that time, These Servers performed well. But, Now We have come to know that these 2 Machines are quite slow when comparing to the first week. So, Some say, run iostat to see statictics. I am not familiar with comamnd well. I found below url http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/admin-guide/s1-resource-rhlspec.html And, I have still not understood it fully. Could you pls advice me , If you have experience with iostat? In adition to that, What are the other tools I can use? I have already used, top , vmstat commands Hope to hear from you. -- Thank you Indunil Jayasooriya