<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.6000.16681" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>I am running nginx/0.7.1 on my debian
(2.6.24.3 kernel) system. You can see my nginx.conf here: <A
href="http://pastebin.com/m63c18e1">http://pastebin.com/m63c18e1</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>My system has much iowait: <A
href="http://i27.tinypic.com/288crwm.jpg">http://i27.tinypic.com/288crwm.jpg</A>.
This is due to some disk activity every 5 seconds. Here are some samples of
"vmstat 1":</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Terminal size=2>procs -----------memory---------- ---swap--
-----io---- -system-- ----cpu----</FONT></DIV>
<DIV><FONT face=Arial size=2><FONT face=Terminal> 0
2 0 3188220 41632
61408 0 0 0
2280 9119 6100 1 4 73 22<BR> 0
0 0 3187680 41632
61936 0 0
0 272 10516 8027 1 4 93 2<BR> 0
0 0 3188004 41632
61256 0 0
0 0 9446 6479 1 4 95
0<BR> 0 0 0 3188052 41632
61216 0 0
0 0 9533 6893 1 3 96
0<BR> 0 0 0 3187880 41632
62052 0 0
0 0 10639 8117 2 6 93
0<BR> 0 0 0 3186936 41632
64132 0 0
0 0 9797 6898 1 4 95
0<BR> 1 1 0 3189304 41636
61324 0 0 0
4692 9052 6414 1 4 65 29<BR> 0
3 0 3188508 41636
62656 0 0 0
1124 9107 6302 2 4 72 22<BR> 0
0 0 3187448 41636
63044 0 0
0 0 8601 5591 1 5 87
8<BR> 0 0 0 3184968 41636
65344 0 0
0 0 10273 7832 2 6 92
0<BR> 0 0 0 3184900 41636
65024 0 0
0 0 10104 7827 2 5 93
0<BR> 1 0 0 3181960 41636
68428 0 0
0 0 9675 7242 2 5 93
0<BR> 0 4 0 3183416 41636
68892 0 0 0
9528 7025 3921 1 2 55 42<BR> 0
0 0 3186076 41636
63620 0 0
0 440 8508 5839 1 5 60 35</FONT><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>As you can see in my nginx.conf, I have disabled
logging (even error log). I can not determine where my disk is actually writing,
but what I do know is that it is related to nginx. When our site gets busy
(200mbit traffic), iowait increases. There are no other important processes
running on the server.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>My question now is: Is this normal behaviour and
how can I reduce the iowait?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks, Edo.</FONT></DIV></BODY></HTML>