All good advice. I always wished there was an easy way to see which process was doing the most I/O (e.g., like Windows allows you to). I think that FreeBSD may have a new facility for that. I forget.
--- Puryear Information Technology, LLC Baton Rouge, LA * 225-706-8414 http://www.puryear-it.com Author of "Best Practices for Managing Linux and UNIX Servers" Download your free copy: http://www.puryear-it.com/bestpractices.htm ----- Original Message ----- From: "-ray" <[EMAIL PROTECTED]> To: <General@brlug.net> Sent: Saturday, September 10, 2005 7:13 PM Subject: Re: [brlug-general] high load average - how to reduce > > Run iostat -p 1 and see if you can narrow it down to a particular > disk/partition that is getting nailed. That may give some clues. > Hopefully you don't have everything under one huge root partition (and > this is a great reason why you should not do that). > > Also check vmstat 1 and watch the si (swap in) and so (swap out) columns > to see if you're swapping. A memory problem can manifest itself as a disk > bottleneck if you're excessively swapping. > > Check your logs for faulty/failing disks... and failing disk may cause io > requests to hang... resulting in high io wait. > > I'd suspect mysql before apache. There is a program called mysqltop that > will show the top queries hitting the db. I'd give it a shot. > > ray > > > On Fri, 9 Sep 2005, Petri Laihonen wrote: > >> Hi, >> >> Does anyone know how I can check which application is causing heavy CPU >> iowait on my webserver? I assume it is either Apache or MySql. >> >> Below you can see that load averages are getting very high during the >> day. All the way at the bottom is top section of "top" few minutes after >> restarting apache and mysql >> >> >> Sendmail section of logwatch........ (sendmail is not really used in this >> system except for internal stuff) >> >> Connections Rejected due to load average:: >> Load Avg 100: 4 Times(s) >> Load Avg 102: 1 Times(s) >> Load Avg 104: 1 Times(s) >> Load Avg 108: 1 Times(s) >> Load Avg 24: 48 Times(s) >> Load Avg 25: 33 Times(s) >> Load Avg 26: 30 Times(s) >> Load Avg 27: 32 Times(s) >> Load Avg 28: 18 Times(s) >> Load Avg 29: 16 Times(s) >> Load Avg 30: 8 Times(s) >> Load Avg 31: 14 Times(s) >> Load Avg 32: 12 Times(s) >> Load Avg 33: 14 Times(s) >> Load Avg 34: 11 Times(s) >> Load Avg 35: 13 Times(s) >> Load Avg 36: 11 Times(s) >> Load Avg 37: 15 Times(s) >> Load Avg 38: 12 Times(s) >> Load Avg 39: 19 Times(s) >> Load Avg 40: 13 Times(s) >> Load Avg 41: 13 Times(s) >> Load Avg 42: 12 Times(s) >> Load Avg 43: 12 Times(s) >> Load Avg 44: 13 Times(s) >> Load Avg 45: 10 Times(s) >> Load Avg 46: 2 Times(s) >> Load Avg 47: 3 Times(s) >> Load Avg 48: 3 Times(s) >> Load Avg 50: 2 Times(s) >> Load Avg 51: 4 Times(s) >> Load Avg 52: 3 Times(s) >> Load Avg 54: 2 Times(s) >> Load Avg 56: 2 Times(s) >> Load Avg 57: 1 Times(s) >> Load Avg 58: 2 Times(s) >> Load Avg 60: 3 Times(s) >> Load Avg 61: 1 Times(s) >> Load Avg 62: 4 Times(s) >> Load Avg 63: 1 Times(s) >> Load Avg 64: 2 Times(s) >> Load Avg 65: 1 Times(s) >> Load Avg 68: 1 Times(s) >> Load Avg 69: 1 Times(s) >> Load Avg 72: 2 Times(s) >> Load Avg 73: 1 Times(s) >> Load Avg 75: 2 Times(s) >> Load Avg 78: 1 Times(s) >> Load Avg 81: 2 Times(s) >> Load Avg 82: 1 Times(s) >> Load Avg 84: 1 Times(s) >> Load Avg 85: 2 Times(s) >> Load Avg 88: 1 Times(s) >> Load Avg 89: 1 Times(s) >> Load Avg 90: 1 Times(s) >> Load Avg 92: 1 Times(s) >> Load Avg 93: 3 Times(s) >> Load Avg 94: 2 Times(s) >> Load Avg 98: 1 Times(s) >> Load Avg 99: 2 Times(s) >> >> 18:09:04 up 7 days, 12:23, 6 users, load average: 21.22, 22.38, 27.27 >> 260 processes: 259 sleeping, 1 running, 0 zombie, 0 stopped >> CPU states: cpu user nice system irq softirq iowait idle >> total 51.6% 0.0% 24.8% 0.2% 0.2% 22.2% 0.5% >> cpu00 54.2% 0.0% 26.2% 0.0% 0.5% 17.6% 1.1% >> cpu01 49.1% 0.0% 23.4% 0.5% 0.0% 26.8% 0.0% >> Mem: 2057204k av, 2039080k used, 18124k free, 0k shrd, 46316k >> buff >> 1488624k actv, 366012k in_d, 30192k in_c >> Swap: 1052248k av, 42752k used, 1009496k free 1586648k >> cached >> >> >> regards, >> Petri >> >> _______________________________________________ >> General mailing list >> General@brlug.net >> http://brlug.net/mailman/listinfo/general_brlug.net >> > > -- > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= > Ray DeJean http://www.r-a-y.org > Systems Engineer Southeastern Louisiana University > IBM Certified Specialist AIX Administration, AIX Support > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= > > > _______________________________________________ > General mailing list > General@brlug.net > http://brlug.net/mailman/listinfo/general_brlug.net > >
