It would be high time for some capable & easy to use IO instrumentation in Linux. This (vmstat) has been the state of the art for ~ 20 years and you often long for something better. Not to mention it's pretty inaccurate sometimes - reports these huge bursts of IO between periods of idleness even though the disk is munching constantly. Especially with write loads.<p>My ideal tool would let me switch a knob to turn on io profiling and then would let me drill down into the trace, show what processes caused the io, was the io like (contiguous vs seek heavy, fsyncs, etc). A second need is report what kind of io a process incurred during its runtime, a bit like "time".<p>I guess much like "perf" now but for io.<p>For all I know all the kernel pieces are there already. We do have some newer tools like iotop/iostat that are small steps forward. But it's pretty quiet.
Also have a look at "dstat - versatile tool for generating system resource statistics".<p>It uses colors, so it's a bit easier to interpret at first sight.<p>It's a simple "emerge dstat" away in Gentoo.
Nice. I would just add one comment. vmstat is very useful if you run VPS. It can be used to easily detect when your hosting provider is overselling the hardware and other users are killing the I/O (which happens to be the biggest bottleneck in VPS as CPU and RAM can be easily shared and sliced)
I spent years typing vmstat into Solaris machines after reading Cockroft's "Sun Performance and Tuning" book. You would think there would be something better these days, Solaris at least moved on to dtrace. Now I use atop on Linux which isn't as low level as dtrace but is much nicer than vmstat.
On a mac, you can try: vm_stat (with an underscore)<p><a href="https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/vm_stat.1.html" rel="nofollow">https://developer.apple.com/library/mac/documentation/Darwin...</a>