Analysing Disk IO Traffic

view story

http://serverfault.com – I am running a web server (Ubuntu 11.04) that exhibits unexpected high write traffic. When the server is not supposed to write at all, the amount of write traffic is comparable to the read traffic. Concerned about unnecessary write operation, I tried to analyzed what is going wrong on the system. I can exclude heavy apache logging or access time issues (using noatime mount configuration). To track down the problem I wanted to see what files where written. Therefore I enabled IO loggin via block_dump (useful blog entry on this topic: sprocket.io). Every filesystem activity will get logged in (HowTos)