misc/133493: 'gpt boot' should mark the slice in the protective mbr
chris at chacal.cjkey.org.uk
Wed Apr 8 10:00:10 PDT 2009
>Synopsis: 'gpt boot' should mark the slice in the protective mbr as active
>Arrival-Date: Wed Apr 08 17:00:09 UTC 2009
>Originator: Christopher Key
>Release: FreeBSD 7.1-RELEASE-p3 amd64
System: FreeBSD chacal.wzl33 7.1-RELEASE-p3 FreeBSD 7.1-RELEASE-p3 #5: Mon Apr 6 23:58:47 BST 2009 root at chacal.wzl33:/usr/obj/usr/src/sys/CHACAL amd64
GPT partitioned disks have a protective mbr in the first sector of the disk, containing code to boot from the disk on non-EFI systems, along with an entry for a single slice covering the entire disk. Some BIOSes, e.g. Intel DQ965GF, will refuse to attempt to boot from a disk without an active slice. A workaround is to mark the slice as active after installing installing the pmbr, i.e.
gpt boot /dev/...
fdisk -a /dev/... (set slice 1 as active)
It would however be preferable for gpt to do this itself, either by default, or by adding a suitable command line option.
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