On Tue, 26 Mar 2013 12:07:59 -0700, Jordan Uggla wrote: > On Tue, Mar 26, 2013 at 6:50 AM, David WE Roberts > <[email protected]> wrote: >> >> Test #3 >> >> Installed Ubuntu 12.04 64 bit to the partition on the GPT drive where >> it was previously installed. >> >> Nominated MBR drive as boot drive. >> >> Same failure as Test #2. >> >> Now, of course, I can't boot anything because when I revert back to a >> full MBR configuration core.img is set up for GPT partitions so can't >> see the MBR partitions, although it can see both MBR discs. >> >> About to rerun Test #2 on the MBR configuration to reset core.img (I >> hope). > > I am very confused about what you're trying to accomplish, and even more > confused about what you've done up to this point. There is no reason > that you should need to get stuck at a grub rescue shell when > transitioning from an msdos label to a GPT label if you run grub-install > properly (meaning, passing the device whose boot sector your BIOS is > going to load, and if needed a proper --boot-directory argument, no > --modules argument should ever be necessary) after making any > partitioning changes. Please re-run grub-install (without --modules) and > note down the exact command you ran, as well as the output of "mount" > when you ran grub-install, and post both. If after that grub-install > command you're still not able to boot, please run boot info script > http://bootinfoscript.sourceforge.net/ from a LiveCD/USB or other > working GNU/Linux installation and post the RESULTS.txt that it > produces.
Will do. However to me what I am doing is very simple. I am booting grub from MBR on disc /dev/sda. It is loading the main part of grub from /dev/sdb1 on MBR disc /dev/sdb. /dev/sdb1 is an ext2 partition which is the root mount point for my Ubuntu filestore; /boot/grub is also on /dev/sdb1 as an integral part of the filestore. All this works fine. However I am moving my /dev/sdb from a 750GiB MBR drive to a 3GiB GPT drive. Because of the extra partition automatically created at the start of a GPT drive the first useable partition on the GPT drive is /dev/sdb2. So (in the simplest example) I am installing a brand new instance of Ubuntu 12.04 64 bit on /dev/sdb2 which contains both the / (root) filestore and also /boot/grub. I am still booting initially (first bits of grub) off MBR disc /dev/sda with the expectation that grub will be able to see /dev/sdb2 on the GPT disc and find /boot/grub with all the information it requires to complete booting. I have assumed that this is what 'part_gpt' is supposed to do. i.e. it should be able to recognise a GPT disc, recognise the partitions within that disc, and then enable grub to access data from one of the partitions. As I understand it this is what 'part_msdos' does with MBR discs. The problem I have is that with 'part_gpt' in core.cfg grub cannot see any partitions (although it sees the MBR disc(s). With both 'part_gpt' and 'part_msdos' in core.cfg grub can see the MBR discs and partitions but still cannot see the GPT disc - so obviously cannot see the GPT partitions either. Bottom line - grub seems unable to recognise my GPT disc even when I have installed a new version of Ubuntu in an ext2 partition on the GPT disc and told it to put grub in the MBR of my MBR disc. Regards David _______________________________________________ Help-grub mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-grub
