Constant disk activity - how can I tell what files are being accessed nonstop?

Solution 1:

You can get a quick bird's eye view using Process Monitor to see what the currently-running processes are doing. This will show you both the processes and the files they're accessing.

Adding the "I/O Read Bytes", "I/O Write Bytes", "I/O Reads", and "I/O Writes" columns to Task Manager can give you some ideas, too.

Longer term, you're probably best off capturing some counter logs w/ Performance Monitor and sifting through the data. The free Performance Analysis of Logs (PAL) tool can give you some decent feedback of overall system performance characteristics.

I'd wonder about whether you're seeing memory paging causing an increase in disk activity. Watch the "Pages Input / sec" counter of the "Memory" object in Performance Monitor. A sustained high count of pages input / sec indicates that you're starved for physical memory, which can manifest itself in excessive disk access.

Solution 2:

I used Filemon for something like this a while ago. Turns out theres a new tool called ProcessMon which does real time registry and file system monitoring.

http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx

Edit - Evan beat me to it; I also like PAL for analysing perfmon counters thats a good tip.