When you run procmon the first thing you are asked to do is to set up a filter (aside from the one time EULA!). What we will do is start procmon and create a filter for just the SQL Data files, because there are processes which constantly read and write to files we want to ignore the general 'chatter'. First you will need a copy of procmon (Process Monitor), which you can download from. CapturingĬapturing the data is very straight forward. To do this we can use the free 'Process Monitor' tool and then load the output into SQL Server.

In this article I will be show how to measure the quantity and size of I/O requests in each database as well as being able to work out where your I/O's are hitting and then matching those up with physical tables. Understanding SQL's I/O patterns can help you design your disk infrastructure and knowing your application's patterns can help you get the most out of your disks. While SSD drives have been hailed as the future and fault tolerant ram drives are prohibitively expensive, most of us still use the humble mechanical disk drive to store and retrieve data.

The single most expensive native operation SQL Server can perform is reading and writing to the disk.

Process monitor file access