Date: Mon, 29 Sep 2003 17:58:10 +1000 From: Peter Jeremy <peterjeremy@optushome.com.au> To: Sergey Babkin <babkin@bellatlantic.net> Cc: hackers@freebsd.org Subject: Re: has anyone installed 5.1 from a SCSI CD? Message-ID: <20030929075809.GA3062@server.c211-28-27-130.belrs2.nsw.optusnet.com.au> In-Reply-To: <3F775D41.DF780001@bellatlantic.net> References: <3F775D41.DF780001@bellatlantic.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Sep 28, 2003 at 06:14:25PM -0400, Sergey Babkin wrote: >BTW, I have another related issue too: since at least 4.7 >all the disk device nodes have charcater device entries in /dev. As of December 1999 - which is before 4.0-RELEASE. This was well advertised and discussed at the time. Your objections are about 4 years too late. >That's very, very wrong. Even though there may be no difference >any more between the charcater and block drivers, the type of >device node still conveys the information about device types >to the applications. One case in point being a viewer application >(if anyone is interested, http://nac.sf.net ) which must handle >the sequential and random-access devices differently: 'block' vs 'character' has nothing to do with random or sequential access and any application that thinks it does is broken. Any application that directly accesses devices must understand all the various quirks - ability to seek, block size(s) supported, side- effects of operations etc. Yes, block devices must be random access, but character devices can be either random or sequential-only depending on the physical device. The only purpose for block devices was to provide a cache for disk devices. It makes far more sense for this caching to be tightly coupled into the filesystem code where the cache characteristics can be better controlled. Peter
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030929075809.GA3062>