Xref: utzoo comp.unix.wizards:11706 comp.lang.c:13245
Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!uw-beaver!tektronix!orca!tekecs!frip!andrew
From: andrew@frip.gwd.tek.com (Andrew Klossner)
Newsgroups: comp.unix.wizards,comp.lang.c
Subject: Re: Record-access libraries (with query on NFS)
Message-ID: <10467@tekecs.TEK.COM>
Date: 13 Oct 88 15:17:15 GMT
References: <e4G91#2Wa6Tw=eric@snark.UUCP> <287@cvbnet2.UUCP>
Sender: andrew@tekecs.TEK.COM
Organization: Tektronix, Wilsonville, Oregon
Lines: 14


	"If you access the raw disk device do you disable that
	read-ahead and write-behind aspect of the UNIX filesystem
	abstraction?"

Yes.  But note: a raw disk does NOT support a byte stream model (at
least under Berkeley).  It implements a block model only.  An
application that tries to do a read(2) or write(2) beginning with a
byte that does not begin a block will find that its lseek pointer is
rounded down to the beginning of the block.  This burned some
application writers here.

  -=- Andrew Klossner   (uunet!tektronix!tekecs!frip!andrew)    [UUCP]
                        (andrew%frip.gwd.tek.com@relay.cs.net)  [ARPA]