Date: Sun, 19 Oct 1997 20:21:26 -0500 (EST) From: "John S. Dyson" <toor@dyson.iquest.net> To: proff@iq.org Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: nasty problem with vnode and other disk drivers? Message-ID: <199710200121.UAA05647@dyson.iquest.net> In-Reply-To: <19971020010910.4635.qmail@iq.org> from "proff@iq.org" at "Oct 20, 97 11:09:09 am"
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proff@iq.org said: > > > > > It isn't expected behavior, but raw, block devices currently need I/O on > > 512 byte boundarys for integrals of 512 byte lengths. > > > > John > > > > > > > > /dev/rvn0 is a character device. /dev/vn0 is the block device. > I understand, as I said (raw, block device) is a type of character device. So is a tty. Try seeking on a tty -- it won't skip characters, but it is possible to implement. Such (raw, block device) types usually support aligned transfers only (even on some SVR4 derivatives.) If you want to do unaligned transfers, it is best to do some buffering. There might be something coming along in the future, but not now. -- John dyson@freebsd.org jdyson@nc.com
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