From owner-freebsd-questions Sun Feb 21 11:24:52 1999 Delivered-To: freebsd-questions@freebsd.org Received: from alpha.comkey.com.au (alpha.comkey.com.au [203.9.152.215]) by hub.freebsd.org (Postfix) with SMTP id 307D31167C for ; Sun, 21 Feb 1999 11:24:41 -0800 (PST) (envelope-from gjb@comkey.com.au) Received: (qmail 8282 invoked by uid 1001); 21 Feb 1999 03:33:49 -0000 Message-ID: <19990221033349.8281.qmail@alpha.comkey.com.au> X-Posted-By: GBA-Post 1.04 06-Feb-1999 X-PGP-Fingerprint: 5A91 6942 8CEA 9DAB B95B C249 1CE1 493B 2B5A CE30 Date: Sun, 21 Feb 1999 13:33:49 +1000 From: Greg Black To: Greg Lehey Cc: Kenneth Chiu , freebsd-questions@FreeBSD.ORG, gjb@alpha.comkey.com.au Subject: Re: BSD filesystems & MBR References: <19990220010713.3722.qmail@alpha.comkey.com.au> <19990221104540.V93492@lemis.com> In-reply-to: <19990221104540.V93492@lemis.com> of Sun, 21 Feb 1999 10:45:40 +1030 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > >>> Optionally, but not recommended, you can make the disk "dangerously > >>> dedicated". > >> > >> I keep seeing references that repeat this advice, but I have not > >> seen any compelling reasons for it. Is there any real reason > >> why, on a machine that will never run anything but FreeBSD, this > >> could present a problem? > > > > The only "real" reason that I know of is the one that came across > > the lists recently. As I understand it, the BIOS on a particular > > machine gets confused by the absence of a "normal" partition table, > > causing it to pass bogus data to the boot blocks. > > Correct, I've heard this too. I've seen a lot of discussion on the > subject, and I'm no wiser. Some claim that dangerously dedicated > disks don't work at all with modern BIOSes; others make a distinction > between safely dedicated and dangerously dedicated. All don't supply > enough information to convince me, but I haven't had time to look at > it myself. I've been using the equivalent of "dangerously dedicated" disks on both IDE and SCSI disks on a range of PCs from a 486-33 that dates back to 1991 up to boxes built in the last couple of weeks running various releases of BSD/OS and FreeBSD. I have never had any problems with this, and don't expect to (since I'll only ever switch to different BSD versions). I certainly don't buy the theory about dangerously dedicated disks not working at all with modern BIOSes -- unless this is something that is supposed to show up in random use some time after a successful installation, which sounds far-fetched to me. I'm guessing here, but it looks as though any problems should declare themselves when you first install to a new disk if they are going to happen at all. Does anybody have an informed opinion on this last theory? -- Greg Black To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message