Re: Random performance hit, unknown cause.

On Thu, Apr 12, 2012 at 3:41 PM, Brian Fehrle
<brianf@consistentstate.com> wrote:
> This morning, during our nightly backup process (where we grab a copy of the
> data directory), we started having this same issue. The main thing that I
> see in all of these is a high disk wait on the system. When we are
> performing 'well', the %wa from top is usually around 30%, and our load is
> around 12 - 15. This morning we saw a load  21 - 23, and an %wa jumping
> between 60% and 75%.
>
> The top process pretty much at all times is the WAL Sender Process, is this
> normal?

Sounds like vacuum to me.