From owner-freebsd-hackers Mon Mar 5 17:25: 1 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from earth.backplane.com (earth-nat-cw.backplane.com [208.161.114.67]) by hub.freebsd.org (Postfix) with ESMTP id 89F8137B718 for ; Mon, 5 Mar 2001 17:24:58 -0800 (PST) (envelope-from dillon@earth.backplane.com) Received: (from dillon@localhost) by earth.backplane.com (8.11.2/8.9.3) id f261OwH48293; Mon, 5 Mar 2001 17:24:58 -0800 (PST) (envelope-from dillon) Date: Mon, 5 Mar 2001 17:24:58 -0800 (PST) From: Matt Dillon Message-Id: <200103060124.f261OwH48293@earth.backplane.com> To: Dan Phoenix Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: systat -vmstat or iostat IO help References: Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :Well we use php mostly. I noticed from moving from php3 to php4 :memory consumption on webservers was just incredible and had to :increase ram from 256 megs to 500megs on each of webservers. :Memory is fine now. : :[root@lotho dphoenix]# ps aux|grep httpd|wc -l : 65 :[root@lotho dphoenix]# top |grep -i mem :Mem: 193M Active, 138M Inact, 89M Wired, 33M Cache, 61M Buf, 46M Free :[root@lotho dphoenix]# uptime : 5:06PM up 2 days, 23:51, 1 user, load averages: 3.29, 1.94, 1.70 :[root@lotho dphoenix]# : :load is down now cause peak is off but systat -vm 1 showed about 3-4 :seconds of 100% then 1 sec of 0 then 3-4 sec of 100% again...etc. :Another factor is mysql with persistant database connections. :Waiting on a request back from the mysql server could cause some IO You shouldn't have 46MB free. You should have maybe 10MB free. 46MB free would seem to indicate that some progrma is eating a large chunk of memory and then exiting, blowing a big piece of the disk cache away in the process. I would monitor the machine's memory and disk I/O closely to try to figure out which process or processes are responsible. :as well i could imagine...another factor. Only thing I have never been :able to figure out is how to kill persistant connections when a mysql :server goes down. Let's say i drop a mysql server....all the webservers :will use up all ram and swap till machine just drops using up all it's :resources.....effect on freebsd is unable to free vm free_pages and Dunno, but it sounds like a problem you need solve. At the very least set Apache's connection limit so Apache stops working before the machine would otherwise die. :But I am going offtopic....memory is not an issue. So real question :is how to calculate then if the drive is doing more than say 166 seeks on :disk per sec. Any great tool out there :) Memory is always an issue when you have a saturated drive unless the saturation is being caused by a lots of write I/O. For a script, probably the easiest thing to do is to pipe (the continuous) 'iostat ad0 10' output to a script and have the script pull out the tps field and do something with it. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message