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]"
