From owner-freebsd-fs@FreeBSD.ORG Mon Mar 23 16:49:11 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 70C351065680 for ; Mon, 23 Mar 2009 16:49:11 +0000 (UTC) (envelope-from mel.flynn+fbsd.fs@mailing.thruhere.net) Received: from mailhub.rachie.is-a-geek.net (rachie.is-a-geek.net [66.230.99.27]) by mx1.freebsd.org (Postfix) with ESMTP id 423E58FC15 for ; Mon, 23 Mar 2009 16:49:11 +0000 (UTC) (envelope-from mel.flynn+fbsd.fs@mailing.thruhere.net) Received: from sarevok.dnr.servegame.org (gate.lan.rachie.is-a-geek.net [192.168.2.10]) by mailhub.rachie.is-a-geek.net (Postfix) with ESMTP id 5CC177E818 for ; Mon, 23 Mar 2009 08:33:53 -0800 (AKDT) From: Mel Flynn To: freebsd-fs@freebsd.org Date: Mon, 23 Mar 2009 17:33:50 +0100 User-Agent: KMail/1.11.0 (FreeBSD/8.0-CURRENT; KDE/4.2.0; i386; ; ) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200903231733.51671.mel.flynn+fbsd.fs@mailing.thruhere.net> Subject: Trying to understand how aio(4), mount(8) async (and gjournal) relate X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Mar 2009 16:49:11 -0000 Hello list, in an effort to try and understand the various async systems available, it's unclear to me how (if at all) the above relate. If one mounts a disk with async, does this internally use aio system calls, or is there a subsystem available which does largely the same? If so, why are there 2 subsystems? When using aio, for example with squid, does this mean the underlying provider needs to be mounted async or is this totally unrelated? Similarly if said disk is on a gjournalled partition, is the async mount redundant or is using aio redundant or neither? The systems themselves are properly documented - I just couldn't find any info on how they relate, or why they are unrelated. -- Mel