[nSLUG] uefi and gpt

Robin Murray nibor.yarrum at gmail.com
Wed Jan 22 13:52:03 AST 2014


I just wanted to give everyone a heads up on newer system you might want to
install linux on. This may be old news to many, but where I don't work on
new systems that often, it blind sided me.

There are two new features added to newer systems (pretty much anything
with windows 8+ now, and a few older ones with 7 as well). One is a secure
boot feature called uefi that replaces the bios and enhances the boot
process to make it more secure, the other is gpt partitioning which changes
how disks are partitioned. There are lots of hits on google if you want the
gory details.

The problem that I ran in to is that we are currently in the worst possible
spot in supporting these new features in our tooling (both linux and
windows thrid party). When new stuff is introduced, no one supports it and
you are relatively safe. After new stuff has become old hat, everything is
supported nicely and no one give it a second thought. Between those
extremes you get spotty and unreliable support, and that's when major
problems can rear their ugly heads. You believe you are using proper
tooling, and they betray you.

My horror story: I purchased a new dell laptop with win8 installed. I also
purchased an ssd to replace the 1Tb hard drive since I'm more interested in
speed than space. The toshiba ssd came with some cloning software called
ntiecho. I plunked this cd in and it asked me to install it, which I did,
and it immediately made my source hdd drive unbootable because it didn't
properly support uefi. It installed a grub menu with two options, one to
start the cloning process, the other to restore back to windows boot,
neither one of which worked. Not an auspicious start. (On a side note, it
really sticks in my craw that cloning software would screw around with the
boot areas on a source drive at all, let alone without any warning.
Unbelievable!)

>From there I disappeared down a rabbit hole for four days in my spare time
trying to get the system bootable from the ssd. Used clonezilla, windows
recovery, kubuntu live and lots of other tools, and was lead down one
branch of the maze after another.

One of the major problems is that dell, in its infinite wisdom, doesn't
provide a windows disk, just a paritition on the hdd, to recover the
system. I was able to get this recovery partition onto a live usb stick and
boot to it, but again, in dell's infinite wisdom, the recovery software is
a dell version, not the windows version, and it's useless, it just tries a
few things behind the scenes to try to fix the problem, and if it can't
find anything wrong, gives up and tries to factory restore. No access to
diskpart or bcdedit or any other recovery tools, just a brain dead single
window with no options. And factory restore does NOT fix the boot
partitions. So if you screw up your boot partitions, you are done as far as
dell recovery goes.

Other things of note:
* kparted on kubuntu 12.04.3 says it supports gpt, but doesn't, it screws
things up. gparted does work, however.
* gdisk can be used to work with gpt partitions, and seems to work well
(you can even sort you partitions in the order they appear on the drive,
which is nice).
* when you install linux, create a small (1Mb) 'grub-boot' partition, that
seems to be where the grub menuing system is now stored. If you don't do
that, you only get options in the efi menu for the current linux install.
* If installing from scratch, also create a small (100-500Mb) efi partition
where the efi boot process is stored. This is a shared partition between
os's, so you will see windows boot stuff there too if you have windows. If
windows efi is pre-installed, just point the linux install to it so it will
insert its own stuff.
* If you want to clone a windows setiup, for now (until all the tools are
properly enhanced), do the clone first and put all the windows partitions
at the front of the drive, in the same order as they were on the source
drive, then install linux on subsequent partitions. Otherwise you will be
faced with drive letter problems on windows, and possibly get hauled in to
fixing bool stuff with borked tools.
* If you want to resize the windows ntfs partitions before the clone,
resize them first within windows rather than using an external tool that
may not properly support gpt.
* If windows tells you that you can't shrink your os partition down to the
size you want, even though you haven't used all the space, you have to
figure out what unmovable files are in the way. I had to temporarily turn
off swap file and system recovery before I could shrink it to fit my ssd.
* Before you start, try to get hold of a full windows install disk you can
use to recover from, or barring that, at least a full system image of your
new system so you can blast everything back and start from scratch. Dell
offers a cd and usb stick, but you have to order them separately. I now
have a usb stick coming to me so I can reset my borked source drive.
* Read up on uefi, efi boot partitions, grub-boot partitions, gpt, gdisk,
bcdedit, bootrec, secure boot and anything else you can get hold of before
diving in. Otherwise be ready for the guys in the white suits to yank you
away.

Hopefully these tips will be of some use to people here and save your
sanity.

Good luck and godspeed.


--
Robin Murray
Hatchet Lake,
Nova Scotia
Canada
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