> It was 78816 and you traced 78815? Are you sure the process with 24h of
> CPU was pgstat?
>
I'm sorry that was a typo. Of course I traced the good process (proof is
that at the end it renamed a file to "global/pgstat.stat".
And yes, "top" showed 24H in the TIME column and 99% in the WCPU column.
Also this process used 50-90% of disk I/O continuously, slowing down the
computer.
I'm sure that it will happen again, then I'm going to post another trace
(and make sure that I trace the good process).
Best,
Laszlo