From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: Time to deprecate old RAID formats? Date: Thu, 01 Nov 2007 14:02:24 -0700 Message-ID: <472A3EE0.3090503@zytor.com> References: <18200.49267.763509.924873@stoffel.org> <18200.53593.687483.120827@stoffel.org> <1192810534.1666.68.camel@firewall.xsintricity.com> <471A0C02.4030407@msgid.tls.msk.ru> <18202.5687.672431.295590@stoffel.org> <471A47CC.1070508@msgid.tls.msk.ru> <18205.2688.952701.567195@stoffel.org> <1193186569.10336.30.camel@firewall.xsintricity.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1193186569.10336.30.camel@firewall.xsintricity.com> Sender: linux-raid-owner@vger.kernel.org To: Doug Ledford Cc: John Stoffel , Michael Tokarev , linux-raid@vger.kernel.org List-Id: linux-raid.ids Doug Ledford wrote: >> >> I would argue that ext[234] should be clearing those 512 bytes. Why >> aren't they cleared > > Actually, I didn't think msdos used the first 512 bytes for the same > reason ext3 doesn't: space for a boot sector. > The creators of MS-DOS put the superblock in the bootsector, so that the BIOS loads them both. It made sense in some diseased Microsoft programmer's mind. Either way, for RAID-1 booting, the boot sector really should be part of the protected area (and go through the MD stack.) The bootloader should deal with the offset problem by storing partition/filesystem-relative pointers, not absolute ones. -hpa