I've been trying to study various other threads, such as
and http://ubuntuforums.org/showthread.php?t=1838078 in an attempt to set up a newly-purchased Seagate 3TB external USB drive with GPT partitioning and use it to boot Ubuntu Oneiric and, in the future, additional Linux distributions, without perturbing my day-to-day laptop configuration.
My laptop is a 3.5 year old HP dv9000z with 4GB of memory, AMD Turion64 dual core CPU, NVIDIA GeForce 6150 graphics and a relatively vanilla Phoenix BIOS with, apparently, no (U)EFI capabilities. There are TWO 80GB SATA disk drives installed, the primary has Windows XP Media Edition (and its maintenance/re-installation partition), and the other drive has openSUSE 11.4.
GRUB 0.97 was installed by openSUSE, and I can either let it
boot openSUSE 11.4 automatically, or select Windows XP if I
really want to boot that. I have a Western Digital 250GB external
USB drive with standard old-fashioned MBR partitions and GRUB 0.97 (+/-, i.e. NOT GRUB2), and when it's plugged in prior to power-up, I can then boot various other distributions (Fedora, Natty, Mageia, ...) as desired. Yes, the BIOS boot device ordering is set correctly: DVD/CD, USB disk, internal hard disk, USB Floppy, ...
I'm trying to do something like that with the new 3TB. After
some fits and starts, I installed 'gdisk' on my openSUSE 11.4
system and used it to repartition using GPT. This drive has
4096 byte sectors. I've even been able to install Oneiric into a partition, and Fedora 16 to two others (/, /boot) as the latter is rumored to finally being able to cope with GPT and GRUB2.
However, I've not been able to boot either system and, in fact, can't even get a "GRUB>" prompt - the BIOS acts like the drive isn't there and starts the GRUB 0.97 on the first hard drive.
(As an aside, I have an Acer Aspire netbook with an Insyde H2O
EFI BIOS that boots an external 1TB with GPT and Ubuntu/Natty's
GRUB2 beautifully). openSUSE 11.4 comes up smiling, although the drive ordering is different (the 3TB shows up as /dev/sdb, the
Windows disk is /dev/sda, the openSUSE 11.4 disk is /dev/sdc).
My suspicion is that I've messed up the (boot block) and/or other
important partition tables by using gparted, fdisk, and other tools (even if just to look at something). I'm prepared to wipe the drive (dd if=/dev/zero... comes to mind!) as necessary.
Output from gdisk on openSUSE 11.4 as invoked as root, having plugged the 3TB drive in long after booting the system:
I tried to create 1MiB BIOS boot partition (worked nicely on my netbook's 1TB), a 512MB /boot partition for F16 on the second partition, a 4GB swap partition, and then four 100GB partitions, one for each distro of interest. Oneiric is installed on partition 7, Fedora 16 root is on partition 4.
linux-9mjd:/home/obfuscated # gdisk /dev/sdc
GPT fdisk (gdisk) version 0.7.2
Partition table scan:
BSD: not present
APM: not present
Found valid GPT with protective MBR; using GPT.
Command (? for help): print
Disk /dev/sdc: 732566645 sectors, 2.7 TiB
Logical sector size: 4096 bytes
Disk identifier (GUID): D8FDAD5C-8335-46A3-BA1C-D44CF7D2C31E
Partition table holds up to 128 entries
First usable sector is 6, last usable sector is 732566639
Partitions will be aligned on 256-sector boundaries
Total free space is 626529130 sectors (2.3 TiB)
Number Start (sector) End (sector) Size Code Name
1 256 511 1024.0 KiB EF02 BIOS boot partition
2 512 131583 512.0 MiB EF00 ext4
3 131584 1180159 4.0 GiB 8200 Linux swap
4 1180160 27394559 100.0 GiB 0700 Linux filesystem
5 27394560 53608959 100.0 GiB 8300 Linux filesystem
6 53608960 79823359 100.0 GiB 8300 Linux filesystem
7 79823360 106037759 100.0 GiB EF00 Ubuntu
I've tried reinstalling ("grub-install") GRUB2 several times, even after booting the Oneiric Live CD and chrooting to the on-disk installation and using apt-get to update it to ensure that I had the latest-n-greatest bits. I'm assuming that I either don't understand GPT and GRUB2 well enough, or I've made a rash assumption about what can be legally/safely done. Any help would, of course, be greatly appreciated!
Thanks in Advance!