Date: Tue, 13 Nov 2007 10:42:50 +0300 From: Alexey Popov <lol@chistydom.ru> To: Panagiotis Christias <christias@gmail.com> Cc: freebsd-hackers@freebsd.org, freebsd-stable@freebsd.org Subject: Re: amrd disk performance drop after running under high load Message-ID: <4739557A.6090209@chistydom.ru> In-Reply-To: <e4b0ecef0711111531k449f78fbnf7f3241b768498ad@mail.gmail.com> References: <47137D36.1020305@chistydom.ru> <47149E6E.9000500@chistydom.ru> <4715035D.2090802@FreeBSD.org> <4715C297.1020905@chistydom.ru> <4715C5D7.7060806@FreeBSD.org> <471EE4D9.5080307@chistydom.ru> <4723BF87.20302@FreeBSD.org> <47344E47.9050908@chistydom.ru> <47349A17.3080806@FreeBSD.org> <47373B43.9060406@chistydom.ru> <e4b0ecef0711111531k449f78fbnf7f3241b768498ad@mail.gmail.com>
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Hi. Panagiotis Christias wrote: >>>>> In the "good" case you are getting a much higher interrupt rate but >>>>> with the data you provided I can't tell where from. You need to run >>>>> vmstat -i at regular intervals (e.g. every 10 seconds for a minute) >>>>> during the "good" and "bad" times, since it only provides counters >>>>> and an average rate over the uptime of the system. >>>> Now I'm running 10-process lighttpd and the problem became no so big. >>>> >>>> I collected interrupt stats and it shows no relation beetween >>>> ionterrupts and slowdowns. Here is it: >>>> http://83.167.98.162/gprof/intr-graph/ >>>> >>>> Also I have similiar statistics on mutex profiling and it shows >>>> there's no problem in mutexes. >>>> http://83.167.98.162/gprof/mtx-graph/mtxgifnew/ >>>> >>>> I have no idea what else to check. >>> I don't know what this graph is showing me :) When precisely is the >>> system behaving poorly? > what is your RAID controller configuration (read ahead/cache/write > policy)? I have seen weird/bogus numbers (~100% busy) reported by > systat -v when read ahead was enabled on LSI/amr controllers. ********************************************************************** Existing Logical Drive Information By LSI Logic Corp.,USA ********************************************************************** [Note: For SATA-2, 4 and 6 channel controllers, please specify Ch=0 Id=0..15 for specifying physical drive(Ch=channel, Id=Target)] Logical Drive : 0( Adapter: 0 ): Status: OPTIMAL --------------------------------------------------- SpanDepth :01 RaidLevel: 5 RdAhead : Adaptive Cache: DirectIo StripSz :064KB Stripes : 6 WrPolicy: WriteBack Logical Drive 0 : SpanLevel_0 Disks Chnl Target StartBlock Blocks Physical Target Status ---- ------ ---------- ------ ---------------------- 0 00 0x00000000 0x22ec0000 ONLINE 0 01 0x00000000 0x22ec0000 ONLINE 0 02 0x00000000 0x22ec0000 ONLINE 0 03 0x00000000 0x22ec0000 ONLINE 0 04 0x00000000 0x22ec0000 ONLINE 0 05 0x00000000 0x22ec0000 ONLINE I tried to run with disabled Read-ahead, but it didn't help. With best regards, Alexey Popov _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"
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