Date: Sun, 12 May 2002 20:45:53 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Terry Lambert <tlambert2@mindspring.com> Cc: Szilveszter Adam <sziszi@bsd.hu>, freebsd-current@FreeBSD.ORG Subject: Re: Special fx with disklabel(8)? Message-ID: <2198.1021229153@critter.freebsd.dk> In-Reply-To: Your message of "Sun, 12 May 2002 11:35:18 PDT." <3CDEB5E6.17F4509B@mindspring.com>
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In message <3CDEB5E6.17F4509B@mindspring.com>, Terry Lambert writes: >DOS partition tables use a 24b C/H/S value. With 512B sectors, this >means they are incapable of representing more than 8G of disk space. Ahh, I love these time-warp emails from Terry. [*] This is the way the world looked circa 1990. I doubt any normal person has any MBR records which hasn't valid contents in the 32 bit sector count fields which have been part of the MBR record from at least 1994, and probably earlier. Please do not follow Terrys advice, unless and until you have independent confirmation that his 10 year old knowledge is still current. Poul-Henning [*] Not! > >To support a 32b sector offset, you have to go to LBA mode. This >isn't really supported by any BIOS that still respects the C/H/S >offsets, since they will override. > >What probably happened is that you had an overflow that wrapped >you back to the start of the disk. > >The general answer on this is: use "dangerously dedicated mode for >very large disks". > >It's possible to work around this, but it's really a pain, and you >have to know what you are doing. Chapter 5 of the PReP specification >has an excellent tutorial on LBA addressing and DOS partition tables >(much better than any Intel related information I have seen to date), >if you want to fix this problem, rather than just ignoring it. > >-- Terry > >To Unsubscribe: send mail to majordomo@FreeBSD.org >with "unsubscribe freebsd-current" in the body of the message > -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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