So I've got a server that's struggling under the weight of several Wordpress installs. Things are relatively well cached (I am planning to improve things anyway) but I can quickly see that disk IO is extremely high.
I have used iotop
to see that it's mostly PHP honking on the disk but I would really like to know which files. I feel that if I knew that, I might be able to spot additional issues or find a bottleneck that could be widened (move stuff to ram-disk, etc).
So I'm looking for a command that will give me a list of open files, ranked by their IO over the time since the command began. Or something that works on a set period, like 60 seconds.
Note: I'm looking for more than lsof
— I need the output ranked by total IO throughput.