Date: Thu, 14 Jun 2012 20:49:32 +0400 From: "Andrey V. Elsukov" <bu7cher@yandex.ru> To: Olivier Smedts <olivier@gid0.org> Cc: current@freebsd.org Subject: Re: CFR: backup GPT header support in pmbr and loader(8) (Re: Handbook mirroring section) Message-ID: <4FDA161C.80101@yandex.ru> In-Reply-To: <CABzXLYMbZi78FZgUcMRUJA1a41cRaSHMDGydTz_VDnk73fHGQQ@mail.gmail.com> References: <4FCF3021.5070802@FreeBSD.org> <20120606.200735.1551208261335301113.hrs@allbsd.org> <4FD05573.70801@FreeBSD.org> <20120610.224813.710171778841273502.hrs@allbsd.org> <4FD9D4DF.9090609@FreeBSD.org> <CABzXLYPzgBmxGUMhbMSSa7Qxoo4pC4t8%2Bv1t_v6=9HMyP4LGmQ@mail.gmail.com> <4FD9EC14.8070203@FreeBSD.org> <CABzXLYMbZi78FZgUcMRUJA1a41cRaSHMDGydTz_VDnk73fHGQQ@mail.gmail.com>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig8A5405B235F51293ED22C5C0 Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: quoted-printable On 14.06.2012 20:05, Olivier Smedts wrote: >> gpart(8) works only when GPT's geom exists, when PMBR is damaged >> GEOM_PART_GPT can't detect GPT and thus you can't use it. >=20 > IMO, GEOM_PART_GPT should not depend on the MBR do detect GPT. That's > the problem which should be fixed ; adding a partition to the MBR is > only a workaround (and what would happen if the sector 0 was > permanently damaged on disk ?). Why does GEOM_PART_GPT depends on the > sector LBA 0 while the GPT header is located at sector LBA 1 ? Don't > know the feasability of this, just saying... :-) When the GPT disk layout is used the disk should contain a Protective MBR at the LBA 0. This is by the UEFI standard. The protective MBR contains one partition record with the type 0xEE, this partition covers the entire space on the disk after the PMBR. The remaining partition records shall each be set to zeros. When the disk capacity exceeds LBA 0xFFFFFFFF this value is used in the size field of PMBR record. --=20 WBR, Andrey V. Elsukov --------------enig8A5405B235F51293ED22C5C0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iQEcBAEBAgAGBQJP2hYcAAoJEAHF6gQQyKF6LlEH/RG4jwMOXB3Ot3EQAmr5rU1v BjPookK8f2ArKhnfp1tI0A7ytJ17SlGMdlyyHrH1E5g1TphPVOuiXiXG0SWAfOr0 xt0HWOsWenyzAtEiLdGQ675Fur/V3i9P3442NRviRD6d3uj9B+M6K0B72ClIA6zT Q9bguLT4BP7eZ41NrSDnDSGCyzFlbEMHFI/V1Uu5JJC59somqBPuPDkU91K2Rwnj LSzQYH5rt3L1E8ofPJd7vs9wlSq7sSRLdStW5Atv86BUpvGmcCK6AcRm64LHhFJ5 xfgpPCEIJ7nrp0sE2QQ+cCaYYvDI2Gh1wCym3jMhkip9GnH80ZyPa38DU4/tm70= =0ORw -----END PGP SIGNATURE----- --------------enig8A5405B235F51293ED22C5C0--
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