Date: Sun, 26 Jan 1997 10:46:01 +0100 From: j@uriah.heep.sax.de (J Wunsch) To: freebsd-hackers@FreeBSD.ORG Subject: Re: fdisk headache Message-ID: <Mutt.19970126104601.j@uriah.heep.sax.de> In-Reply-To: <199701260706.SAA20817@godzilla.zeta.org.au>; from Bruce Evans on Jan 26, 1997 18:06:48 %2B1100 References: <199701260706.SAA20817@godzilla.zeta.org.au>
next in thread | previous in thread | raw e-mail | index | archive | help
As Bruce Evans wrote: > >> I think it is bad form to do this.. > > > >Mmmaybe. > > >Of course, there's one thing that won't work with this method: > >nextboot. > Boot selectors won't work either. Since there's nothing to select from. ;-) Right now, there are three reasons to still call it ``dangerously dedicated'': . Since the MBR is identical to the BSD bootstrap, there's no room for things like `nextboot' after the MBR, and you can't replace the MBR by fancy things like a boot selector. Hence, in a system that is not FreeBSD-only, you could at best make drives != #0 ``DD'', and you won't be able to boot select away from that drive once you switched there. (Normally, booteasy allows to wander around back and forth through all the drives.) . Some known rogues like Win95 will happily clobber the dummy fdisk table (and thus the BSD bootstrap) when they first visit the drive -- of course, without asking the operator, since they interpret the term ``Plug and play'' this way. . Some operating systems might choke on that fdisk table afterwards, so if you are going to install something else on such a drive later, it's best do do a ``dd if=/dev/zero of=/dev/rXXX count=100'' before recycling the drive to another task. (The fourth reason has been fixed since: disklabel -B used to clobber sysinstall's fdisk table, and thus invalidated the sliced device names sysinstall leaves in /etc/fstab.) The plus side is: . It's the simplest way to setup a drive at all, since you can use the total number of blocks of the drive for FreeBSD. The drives are run in a mode that is basically the same as workstation and minicomputer Unices used to do for years. . The number of BIOS geometry constraints to care for reduces drastic- ally, so you can usually (*) ignore any geometry issues. (*) I.e., the BIOS's geometry idea involves at least 15 sectors per track, 4 heads, and the root file system is not larger than 30 MB. To summarize: this mode is intended for those who only want to run FreeBSD, and nothing else. I never advised people with mixed configurations to use it. Those who don't spend the slightest idea into using their machine with other operating systems can however simplify their life by using it. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Mutt.19970126104601.j>