If you're mirroring the disk with gmirror, how are you dual-booting the disk?
This discussion is about using gmirror to mirror two entire disks, and then use GPT to partition the mirror device. Dual-booting has no bearing on that, as gmirror is a FreeBSD-only technology. Cheers, Freddie Cash [email protected] On Feb 18, 2012 10:37 PM, "Kevin Oberman" <[email protected]> wrote: > On Fri, Feb 17, 2012 at 1:50 PM, Freddie Cash <[email protected]> wrote: > > On Fri, Feb 17, 2012 at 1:38 PM, Andriy Gapon <[email protected]> wrote: > >> And just in case: > >> Unified Extensible Firmware Interface Specification Version 2.3.1, > Errata A > >> September 7, 2011 says: > >> [snip] > >>> Two GPT Header structures are stored on the device: the primary and the > >>> backup. The primary GPT Header must be located in LBA 1 (i.e., the > second > >>> logical block), and the backup GPT Header must be located in the last > LBA > >>> of the device. > >> > >> I can not see any ambiguity or openness to interpretation in this > paragraph. > > > > Unless it's specified somewhere else (which is possible), in this > > paragraph, "device" does not necessarily mean "physical disk". "Last > > LBA of the device" could be interpreted as "last LBA of the GEOM > > provider". > > > > The beauty of GEOM is that "device" is whatever logical mapping it > provides. > > > > After all, LBAs are logical addresses (it's right there in the name!), > > not hardwired physical sector addresses. ;) If they were hardwired, > > then how would internal sector remapping work? ;) > > Please remember that some disks are dual-boot. FreeBSD may understand > geom has the backup one block from the last LBA on the disk, but no > other OS is likely to do so. > > Unless I am missing something, this should be a non-starter. Totally > unacceptable. The backup belongs in the last and only in the last LBA > on the physical disk. > -- > R. Kevin Oberman, Network Engineer > E-mail: [email protected] > _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
