From owner-svn-doc-all@freebsd.org Sun Mar 6 17:39:27 2016 Return-Path: Delivered-To: svn-doc-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 3B9C1A95AFE; Sun, 6 Mar 2016 17:39:27 +0000 (UTC) (envelope-from jgh@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 0CDC0685; Sun, 6 Mar 2016 17:39:26 +0000 (UTC) (envelope-from jgh@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u26HdQpq064676; Sun, 6 Mar 2016 17:39:26 GMT (envelope-from jgh@FreeBSD.org) Received: (from jgh@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u26HdQV6064675; Sun, 6 Mar 2016 17:39:26 GMT (envelope-from jgh@FreeBSD.org) Message-Id: <201603061739.u26HdQV6064675@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jgh set sender to jgh@FreeBSD.org using -f From: Jason Helfman Date: Sun, 6 Mar 2016 17:39:26 +0000 (UTC) To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r48347 - head/en_US.ISO8859-1/books/arch-handbook/driverbasics X-SVN-Group: doc-head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-doc-all@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "SVN commit messages for the entire doc trees \(except for " user" , " projects" , and " translations" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Mar 2016 17:39:27 -0000 Author: jgh Date: Sun Mar 6 17:39:25 2016 New Revision: 48347 URL: https://svnweb.freebsd.org/changeset/doc/48347 Log: - improve readability Submitted by: Chris Petrik Differential Revision: https://reviews.freebsd.org/D5557 (based on) Modified: head/en_US.ISO8859-1/books/arch-handbook/driverbasics/chapter.xml Modified: head/en_US.ISO8859-1/books/arch-handbook/driverbasics/chapter.xml ============================================================================== --- head/en_US.ISO8859-1/books/arch-handbook/driverbasics/chapter.xml Sun Mar 6 14:44:58 2016 (r48346) +++ head/en_US.ISO8859-1/books/arch-handbook/driverbasics/chapter.xml Sun Mar 6 17:39:25 2016 (r48347) @@ -385,12 +385,17 @@ Closing device "echo". block-devices almost unusable, or at least dangerously unreliable. The caching will reorder the sequence of write operations, depriving the application of the ability to know the - exact disk contents at any one instant in time. This makes - predictable and reliable crash recovery of on-disk data - structures (filesystems, databases etc.) impossible. Since + exact disk contents at any one instant in time. + + + This makes predictable and reliable crash recovery of on-disk + data structures (filesystems, databases etc.) impossible. Since writes may be delayed, there is no way the kernel can report to the application which particular write operation encountered a - write error, this further compounds the consistency problem. + write error, this further compounds the consistency + problem. + + For this reason, no serious applications rely on block devices, and in fact, almost all applications which access disks directly take great pains to specify that character (or