"ac@xxxxxx" <ac@xxxxxx> wrote: > Johnny Tan <johnnydtan@xxxxxxxxx> wrote: >>shared_buffers = 48GB# min 128kB > From the postgresql.conf, I can see that the shared_buffers is > set to 48GB which is not small, it would be possible that the > large buffer cache could be "dirty", when a checkpoint starts, it > would cause a checkpoint I/O spike. > > > I would like to suggest you about using pgtune to get recommended > conf for postgresql. I have seen symptoms like those described which were the result of too many dirty pages accumulating inside PostgreSQL shared_buffers. It might be something else entirely in this case, but it would at least be worth trying a reduced shared_buffers setting combined with more aggressive bgwriter settings. I might try something like the following changes, as an experiment: shared_buffers = 8GB bgwriter_lru_maxpages = 1000 bgwriter_lru_multiplier = 4 -Kevin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
