From owner-freebsd-fs@FreeBSD.ORG Wed May 15 00:19:32 2013 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 23DBDEFF for ; Wed, 15 May 2013 00:19:32 +0000 (UTC) (envelope-from daniel@digsys.bg) Received: from smtp-sofia.digsys.bg (smtp-sofia.digsys.bg [193.68.21.123]) by mx1.freebsd.org (Postfix) with ESMTP id 9E208921 for ; Wed, 15 May 2013 00:19:31 +0000 (UTC) Received: from [193.68.136.216] (digsys216-136.pip.digsys.bg [193.68.136.216]) (authenticated bits=0) by smtp-sofia.digsys.bg (8.14.6/8.14.6) with ESMTP id r4F0JJPQ094360 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Wed, 15 May 2013 03:19:21 +0300 (EEST) (envelope-from daniel@digsys.bg) References: <1966772823.291493.1368362883964.JavaMail.root@erie.cs.uoguelph.ca> <5190335D.9090105@hub.org> <20130513005858.GA73875@icarus.home.lan> <94661399-66AC-4E83-B39B-0426442BB84C@hub.org> Mime-Version: 1.0 (1.0) In-Reply-To: <94661399-66AC-4E83-B39B-0426442BB84C@hub.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Message-Id: <12D600DE-CBAB-40C6-B166-083DE7018E7E@digsys.bg> X-Mailer: iPhone Mail (10B329) From: Daniel Kalchev Subject: Re: NFS Performance issue against NetApp Date: Wed, 15 May 2013 03:19:21 +0300 To: "Marc G. Fournier" Cc: "freebsd-fs@freebsd.org" X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 May 2013 00:19:32 -0000 >=20 >> Probably off-topic but worth pointing out: I do not know about Solaris, >> but Linux has multiple layers of caching, and is well-known for doing >> things like caching (and aggregating!) reads/writes to **block** devices >> (this is why on Linux you have to make sure to avoid caching your >> application use O_DIRECT with open(2) or other mechanisms -- the BSDs do >> not do this, block devices are always non-cached). >=20 > Caching *should* only come into play after the first run of the applicatio= n =E2=80=A6 the first run after a reboot of the server shouldn't have anythi= ng in cache yet for caching to come into play=20 >=20 Or, instead of issuing 30 separate NFS calls over the network, issue just on= e. With more latency the difference will be more pronounced. I believe Jeremy was referring more to the aggregating aspect, which might p= roduce significant difference for poorly written software.=20 Daniel=