On Sun, 2 Oct 2011, Thomas Lunde wrote: > If you don't care about the current contents of either disk, here is one > way to get rid of the error message about GUID partitions being present. > > Boot from a live CD with just these two hard drives attached to the > system. Once booted, open up a terminal window. Use the df command to > see if anything on either drive has been mounted. If so, they will > appear as /dev/sda1 (or similar). No partitions may have been mounted, > if there is just junk on the drives. If a partition has been mounted, > use the command sudo umount /dev/sda1 (or whatever sd partitions you saw > from the df command) to remove them from the df output. > > Use the command ls /dev/sd* to verify that the system "sees" the two > drives and that they are listed as sda and sdb. (You'll want to adjust > the letters below if they come up as something else.) > > Then, issue this command: > sudo dd if=/dev/zero of=/dev/sda bs=1024 count=1024 > and do it again for sdb and any partition tables on the drives will be gone. > > Now, you should be able to follow the installation instructions you've > had. I did that, then used the alternate CD and it fails in the same way that it always fails -- at the end when it tries to install the grub2 loader. I also tried to use fdisk, but it does the same thing as before: $ sudo fdisk /dev/sda WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted. Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel with disk identifier 0xd9ac1ca5. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. I can make a menu list for fdisk options but I don't know which to choose. So I'm still not clear on what I'm supposed to do with fdisk. After I run fdisk the B-o-B instructions might be good, but I can't get there, yet. The sad thing is that after all these dozens of hours of installing, partitioning, re-installing, etc., I feel that it is all there, all installed and ready, but it just won't boot. This seems to describe the problem I am having: http://ubuntuforums.org/showthread.php?t=1631358 I can identify with the guy who spent "three weeks pulling his hair out" only to buy a hardware raid instead of using Ubuntu's software raid. My attempt to save money by using software raid was a very costly miscalculation. So I was trying yesterday to do what some of the readers of that thread seemed to think would solve the problem: "GRUB2 with GPT requires a 1mb partition with the bios_grub flag set (when done in the partitioner I think it's call 'reserved for boot bios') on the beginning of any drives you want to boot which is where it puts the grub kernel. sda and sdb in my case since I want this machine to boot with a degraded array." Unfortunately, it doesn't seem that I am able to understand exactly what this requires. I can't figure out how to do it. I note that Ubuntu alternate CD leaves 1 mb "FREE" before the first RAID partition. I also can't figure out how to install grub2 on the Ubuntu 10.10 (RAID 1) system that apparently has everything except for grub2. It's quite useless without it! The offer to pay someone to do this for me still holds. Mike