Busy busy busy ...

Ever wondered exactly how much disk IO is going on in the background on a Linux box, just in the normal course of operation? Try this;

#!/bin/bash
inotifywait -rm /var | 
while read filename eventlist eventfile
do
	echo $filename $eventlist $eventfile
done

It'll print out a line for each file operation (open/read/close etc) that takes place on the chosen folder (/var in this instance). On my machine I saw something like this;

$ ./notify.sh 
Setting up watches.  Beware: since -r was given, this may take a while!
Watches established.
/var/lib/dbus/ OPEN machine-id
/var/lib/dbus/ ACCESS machine-id
/var/lib/dbus/ CLOSE_NOWRITE,CLOSE machine-id
/var/cache/fontconfig/ CLOSE_NOWRITE,CLOSE c05880de57d1f5e948fdfacc138775d9-le64.cache-4
/var/cache/fontconfig/ CLOSE_NOWRITE,CLOSE 945677eb7aeaf62f1d50efc3fb3ec7d8-le64.cache-4
/var/cache/fontconfig/ CLOSE_NOWRITE,CLOSE 2cd17615ca594fa2959ae173292e504c-le64.cache-4
/var/cache/fontconfig/ CLOSE_NOWRITE,CLOSE 0d8c3b2ac0904cb8a57a757ad11a4a08-le64.cache-4
/var/cache/fontconfig/ CLOSE_NOWRITE,CLOSE a755afe4a08bf5b97852ceb7400b47bc-le64.cache-4

Scary amount of stuff going on ...