Output of dstat is getting buffered (30 seconds)

Question

We are running dstat on a one second update frequency using this option:

--output <filename>

The data is correctly written but only every thirty seconds.

Here is the full dstat command line:

 dstat -tcmdn --vm --output <filename>

The interesting thing is that behavior is happening on our ARM boxes only. On the intel box it is written (/flushed) every second.

So is this a filesystem or dstat issue?

Answer 1

It turns out that the output filesystem (on NFS) was configured for thirty second buffering.

The reason that the one machine (i386) had no delay? The NFS share point is loal for that machine!