From owner-freebsd-hackers Mon Mar 15 10:44:32 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id 10ADD14D74 for ; Mon, 15 Mar 1999 10:44:29 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id KAA01410; Mon, 15 Mar 1999 10:44:01 -0800 (PST) (envelope-from dillon) Date: Mon, 15 Mar 1999 10:44:01 -0800 (PST) From: Matthew Dillon Message-Id: <199903151844.KAA01410@apollo.backplane.com> To: Steve Passe Cc: hackers@FreeBSD.ORG Subject: Re: power-off without halt References: <199903151655.JAA28147@Ilsa.StevesCafe.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :Hi, : : We are looking at using FreeBSD as an "embedded OS" inside a line :of instruments we are building. I think I have a handle on all the :issues except how to cleanly handle shutdown where there is no :console, and thus no way to send a 'halt' command. The requirement :is that the user can merely turn off the power, nothing more required. : : I can modify the disk setup, kernel/util code as needed, I just need some :idea for a workable solution. Has anyone delt with this problem before? : :-- :Steve Passe | powered by :smp@csn.net | Symmetric MultiProcessor FreeBSD Well, physically speaking you can't power off a machine that may be writing to its disk. If it is in the middle of a write, you *will* lose sectors to hard errors. So, typically, the best way to deal with this sort of situation is to mount the disk read-only and never write to it. Or to not have a disk at all. Or to use a pcmcia type flash disk. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message