Maybe Could be Check-Points? I have changed the parameters sometime ago. Follow: effective_cache_size = 200MB
checkpoint_segments = 40 # in logfile segments, min 1, 16MB each checkpoint_timeout = 3min # range 30s-1h #bgwriter_delay = 200ms # 10-10000ms between rounds bgwriter_lru_percent = 16.0 # 0-100% of LRU buffers scanned/round bgwriter_lru_maxpages = 170 # 0-1000 buffers max written/round bgwriter_all_percent = 7.0 # 0-100% of all buffers scanned/round bgwriter_all_maxpages = 400 # 0-1000 buffers max written/round Now I'm having the following problem on vacuum: vacuumdb: vacuuming of database "Postgres" failed: ERRO: multiple active vacuums for index "PartInd_replicacao_historico_sl_log_2-node-1". But there's no anymore vacuum running. 2008/12/8 Scott Marlowe <[EMAIL PROTECTED]> > On Mon, Dec 8, 2008 at 10:17 AM, Rafael Domiciano > <[EMAIL PROTECTED]> wrote: > > Here's the output. While the process was running my database get sometime > > without doing anything. > > You said that I probably get low numbers, but what numbers? > > We're looking for MB/s and the bi/bo fields in bmstat (blocks in / blocks > out) > > > [EMAIL PROTECTED] banco]# time dd if=/dev/zero of=/banco/testfile > bs=1000000 > > count=500 > > 500+0 records in > > 500+0 records out > > 500000000 bytes (500 MB) copied, 85,4485 seconds, 5,9 MB/s > > real 1m25.451s > > user 0m0.003s > > sys 0m1.617s > > [EMAIL PROTECTED] banco]# time dd of=/dev/null if=/banco/testfile > > 976562+1 records in > > 976562+1 records out > > 500000000 bytes (500 MB) copied, 47,5025 seconds, 10,5 MB/s > > real 0m47.543s > > user 0m0.457s > > sys 0m1.470s > > And the vmstat output: > > > > procs -----------memory---------- ---swap-- -----io---- --system-- > > -----cpu------ > > r b swpd free buff cache si so bi bo in cs us sy > id > > wa st > > 0 8 111760 56432 19812 1305692 0 0 744 832 2488 1518 5 3 > 46 > > 46 0 > > Here, the bi/bo numbers are 768 in and 832 out. That's k/second we're > looking at. > > Lots of the same numbers cut out. > > > procs -----------memory---------- ---swap-- -----io---- --system-- > > -----cpu------ > > r b swpd free buff cache si so bi bo in cs us sy > id > > wa st > > 0 6 111760 55452 18528 1296412 0 0 88 25040 1843 1436 2 3 > 34 > > 61 0 > > 1 7 111760 52352 18540 1296472 0 0 36 15220 1467 944 3 2 > 27 > > 68 0 > > 0 6 111760 54152 18552 1296568 0 0 88 42296 1609 822 1 2 > 38 > > 59 0 > > 1 8 111760 52412 18580 1296752 0 0 172 27052 1567 950 2 3 > 27 > > 69 0 > > 0 6 111724 53904 18632 1297008 320 0 580 1504 1902 2320 5 6 > 23 > > 66 0 > > 1 6 111724 54280 18660 1297200 4 0 200 1060 2014 1783 5 3 > 44 > > 48 0 > > 1 7 111676 51388 16340 1302348 8 0 156 1212 1684 848 2 2 > 53 > > 42 0 > > 1 6 111668 55040 14864 1301048 0 4 152 46328 1595 5108 1 5 > 40 > > 54 0 > > Now we're showing that we can write to the disk at 25 to 42 Megs a > second, not too bad. But it looks really bursty, like it can sustain > this throughput for only a few seconds. Try writing a larger file > and run vmstat 10 or 60 as well and see what the average over a longer > time with a larger file is. I get a feeling your machine has a hard > time sustaining throughput for some reason. >
