Le 2 mars 2016 16:25:10 GMT+01:00, Artem Tomyuk <ad...@leboutique.com> a écrit : >Hi. > >I've noticed that autovac. process worked more than 10 minutes, during >this >zabbix logged more than 90% IO disk utilization on db volume.... > >===========>29237 2016-03-02 15:17:23 EET 00000 [24-1]LOG: >automatic vacuum of table "lb_upr.public._reference32": index scans: 1 > pages: 0 removed, 263307 remain > tuples: 298 removed, 1944753 remain, 0 are dead but not yet removable > buffer usage: 67814 hits, 265465 misses, 15647 dirtied > avg read rate: 3.183 MB/s, avg write rate: 0.188 MB/s
According to what I am reading here, your autovacumm avg read activity was less than 4MB/s...and 188kB/s for writes. I seriously doubt these numbers are high enough to saturate your disks bandwidth. > *system usage: CPU 5.34s/6.27u sec elapsed 651.57 sec* This tells that the autovacumm tooks 651s to complete...but only 5s and 6s of cpu in kernel and userland in total. Autovacuum are slowed down thanks to autovacumm_vacuum_cost_delay param, which explains the 10min run and such a low disk activity. >Is it possible to log autovac. io impact during it execution? I would bet the problem is elsewhere... /Ioguix -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
