On Thu, Jul 21, 2022 at 03:59:30PM -0400, bruno da silva wrote: > OS/version: CentOS release 6.9 (Final) How are these set ? tail /sys/kernel/mm/ksm/run /sys/kernel/mm/transparent_hugepage/{defrag,enabled,khugepaged/defrag} /proc/sys/vm/zone_reclaim_mode I suspect you may be suffering from issues with transparent huge pages. I suggest to disable KSM and THP, or upgrade to a newer OS. I've written before about these: https://www.postgresql.org/message-id/20170524155855.GH31097@xxxxxxxxxxxxx https://www.postgresql.org/message-id/20190625162338.GF18602@xxxxxxxxxxxxx https://www.postgresql.org/message-id/20170718180152.GE17566@xxxxxxxxxxxxx https://www.postgresql.org/message-id/20191004060300.GA11241@xxxxxxxxxxxxx https://www.postgresql.org/message-id/20200413144254.GS2228@xxxxxxxxxxxxx https://www.postgresql.org/message-id/20220329182453.GA28503@xxxxxxxxxxxxx On Thu, Jul 21, 2022 at 04:01:10PM -0400, bruno da silva wrote: > The issue started a month ago. Ok .. but how long has the DB been running under this environment ? -- Justin