From owner-freebsd-stable@FreeBSD.ORG Wed Oct 31 00:27:19 2007 Return-Path: Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 504A716A478 for ; Wed, 31 Oct 2007 00:27:19 +0000 (UTC) (envelope-from bright@elvis.mu.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id 424F013C481 for ; Wed, 31 Oct 2007 00:27:19 +0000 (UTC) (envelope-from bright@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1192) id 9BC971A4D81; Tue, 30 Oct 2007 17:27:12 -0700 (PDT) Date: Tue, 30 Oct 2007 17:27:12 -0700 From: Alfred Perlstein To: Dmitry Morozovsky Message-ID: <20071031002712.GG33488@elvis.mu.org> References: <20071029111235.E69594@woozle.rinet.ru> <20071029232403.GE33488@elvis.mu.org> <20071030122816.U39332@woozle.rinet.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071030122816.U39332@woozle.rinet.ru> User-Agent: Mutt/1.4.2.3i Cc: stable@freebsd.org Subject: Re: rrdtool performance tuning (fwd) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 31 Oct 2007 00:27:19 -0000 * Dmitry Morozovsky [071030 02:30] wrote: > On Mon, 29 Oct 2007, Alfred Perlstein wrote: > > AP> * Dmitry Morozovsky [071029 12:44] wrote: > AP> > > AP> > [hmm, after thinking a bit I decided it would be more appropriate here, in > AP> > stable@] > AP> > > AP> > Dear colleagues, > AP> > > AP> > any hints to tune rrdtool with ~30k rrd files (approx 2k target devices)? > AP> > > AP> > machine is mostly IO-bound, showing 100% disk load with 8 or sometimes even 3 > AP> > mB/s, 300-400 tps (it's 2 SATA300 disks in gmirror) > AP> > AP> More ram? > > Already 2G, mostly inactive/free. > > AP> > AP> Turn off atime? > > For sure, and even tried to move rrd data to smaller UFS2 - same result. > > AP> Hash the data files into multiple directories to avoid having 2k files > AP> in one dir. > > Hmm, I thought 2k is not so much, especially where UFSDIRHASH is in place... > > AP> Not sure how rrd tool works internally, but it might make sense > AP> to see if you can use some layering library to force it to cache > AP> some open files per process or something. > > It seems it using a lot of mmap... My try hacking the code and adding MAP_NOSYNC to the call to mmap(2). Try hacking the code to keep the file mapped instead of open/closing it on each access. -Alfred