Friday, November 20, 2015

Converting an existing installation to LUKS using luksipc

This is a burst of notes that I wrote in an e-mail in June when asked about it, and I'm not going to have any better steps since I don't remember even that amount as back then. I figured it's better to have it out than not.

So... if you want to use LUKS In-Place Conversion Tool, the notes below on converting a shipped-with-Ubuntu Dell XPS 13 Developer Edition (2015 Intel Broadwell model) may help you. There were a couple of small learnings to be had...
The page itself is good and without errors, although funnily uses reiserfs as an example. It was only a bit unclear why I did save the initial_keyfile.bin since it was then removed in the next step (I guess it's for the case you want to have a recovery file hidden somewhere in case you forget the passphrase).

For using the tool I booted from a 14.04.2 LTS USB live image and operated there, including downloading and compiling luksipc in the live session. The exact reason of resizing before luksipc was a bit unclear to me at first so I simply indeed resized the main rootfs partition and left unallocated space in the partition table.

Then finally I ran ./luksipc -d /dev/sda4 etc.

I realized I want /boot to be on an unencrypted partition to be able to load the kernel + initrd from grub before entering into LUKS unlocking. I couldn't resize the luks partition anymore since it was encrypted... So I resized what I think was the empty small DIAGS partition (maybe used for some system diagnostic or something, I don't know), or possibly the next one that is the actual recovery partition one can reinstall the pre-installed Ubuntu from. And naturally I had some problems because it seems vfatresize tool didn't do what I wanted it to do and gparted simply crashed when I tried to use it first to do the same. Anyway, when done with getting some extra free space somewhere, I used the remaining 350MB for /boot where I copied the rootfs's /boot contents to.

After adding the passphrase in luks I had everything encrypted etc and decryptable, but obviously I could only access it from a live session by manual cryptsetup luksOpen + mount /dev/mapper/myroot commands. I needed to configure GRUB, and I needed to do it with the grub-efi-amd64 which was a bit unfamiliar to me. There's also grub-efi-amd64-signed I have installed now but I'm not sure if it was required for the configuration. Secure boot is not enabled by default in BIOS so maybe it isn't needed.

I did GRUB installation – I think inside rootfs chroot where I also mounted /dev/sda6 as /boot (inside the rootfs chroot), ie mounted dev, sys with -o bind to under the chroot (from outside chroot) and mount -t proc proc proc too. I did a lot of trial and effort so I surely also tried from outside the chroot, in the live session, using some parameters to point to the mounted rootfs's directories...

I needed to definitely install cryptsetup etc inside the encrypted rootfs with apt, and I remember debugging for some time if they went to the initrd correctly after I executed mkinitramfs/update-initramfs inside the chroot.

At the end I had grub asking for the password correctly at bootup. Obviously I had edited the rootfs's /etc/fstab to include the new /boot partition, I changed / to be "UUID=/dev/mapper/myroot /     ext4    errors=remount-ro 0       ", kept /boot/efi as coming from the /dev/sda1 and so on. I had also added "myroot /dev/sda4 none luks" to /etc/crypttab. I seem to also have GRUB_CMDLINE_LINUX="cryptdevice=/dev/sda4:myroot root=/dev/mapper/myroot" in /etc/default/grub.

The only thing I did save from the live session was the original partition table if I want to revert.

So the original was:

Found valid GPT with protective MBR; using GPT.
Disk /dev/sda: 500118192 sectors, 238.5 GiB
Logical sector size: 512 bytes
First usable sector is 34, last usable sector is 500118158
Partitions will be aligned on 2048-sector boundaries
Total free space is 6765 sectors (3.3 MiB)
Number  Start (sector)    End (sector)  Size       Code  Name
1            2048         1026047   500.0 MiB   EF00  EFI system partition
2         1026048         1107967   40.0 MiB    FFFF  Basic data partition
3         1107968         7399423   3.0 GiB     0700  Basic data partition
4         7399424       467013631   219.2 GiB   8300
5       467017728       500117503   15.8 GiB    8200

And I now have:

Number  Start (sector)    End (sector)  Size       Code  Name

1            2048         1026047   500.0 MiB   EF00  EFI system partition
2         1026048         1107967   40.0 MiB    FFFF  Basic data partition
3         1832960         7399423   2.7 GiB     0700  Basic data partition
4         7399424       467013631   219.2 GiB   8300
5       467017728       500117503   15.8 GiB    8200
6         1107968         1832959   354.0 MiB   8300

So it seems I did not edit DIAGS (and it was also originally just 40MB) but did something with the recovery partition while preserving its contents. It's a FAT partition so maybe I was able to somehow resize it after all.

The 16GB partition is the default swap partition. I did not encrypt it at least yet, I tend to not run into swap anyway ever in my normal use with the 8GB RAM.

If you go this route, good luck! :D

Monday, June 08, 2015

Quick Look: Dell XPS 13 Developer Edition (2015) with Ubuntu 14.04 LTS

I recently obtained the newest Dell's Ubuntu developer offering, XPS 13 (2015, model 9343). I opted in for FullHD non-touch display, mostly because of better battery life, the actual no need for higher resolution, and matte screen which is great outside. Touch would have been "nice-to-have", but in my work I don't really need it.

The other specifications include i7-5600U CPU, 8GB RAM, 256GB SSD [edit: lshw], and of course Ubuntu 14.04 LTS pre-installed as OEM specific installation. It was not possible to directly order it from Dell site, as Finland is reportedly not online market for Dell... The wholesale company however managed to get two models on their lists and so it's now possible to order via retailers. [edit: here are some country specific direct web order links however US, DE, FR, SE, NL]

In this blog post I give a quick look on how I started up using it, and do a few observations on the pre-installed Ubuntu included. I personally was interested in using the pre-installed Ubuntu like a non-Debian/Ubuntu developer would use it, but Dell has also provided instructions for Ubuntu 15.04, Debian 7.0 and Debian 8.0 advanced users among else. Even if not using the pre-installed Ubuntu, the benefit from buying an Ubuntu laptop is obviously smaller cost and on the other hand contributing to free software (by paying for the hardware enablement engineering done by or purchased by Dell).


The Black Box. (and white cat)

Opened box.

First time lid opened, no dust here yet!
First time boot up, transitioning from the boot logo to a first time Ubuntu video.
A small clip from the end of the welcoming video.
First time setup. Language, Dell EULA, connecting to WiFi, location, keyboard, user+password.
Creating recovery media. I opted not to do this as I had happened to read that it's highly recommended to install upgrades first, including to this tool.
Finalizing setup.
Ready to log in!
It's alive!
Not so recent 14.04 LTS image... lots of updates.

Problems in the First Batch

Unfortunately the first batch of XPS 13:s with Ubuntu are going to ship with some problems. They're easy to fix if you know how to, but it's sad that they're there to begin with in the factory image. There is no knowledge when a fixed batch will start shipping - July maybe?

First of all, installing software upgrades stops. You need to run the following command via Dash → Terminal once: sudo apt-get install -f (it suggests upgrading libc-dev-bin, libc6-dbg, libc6-dev and udev). After that you can continue running Software Updater as usual, maybe rebooting in between.

Secondly, the fixed touchpad driver is included but not enabled by default. You need to enable the only non-enabled ”Additional Driver” as seen in the picture below or instructed in Youtube.

Dialog enabling the touchpad driver.

Clarification: you can safely ignore the two paragraphs below, they're just for advanced users like me who want to play with upgraded driver stacks.

Optionally, since I'm interested in the latest graphics drivers especially in case of a brand new hardware like Intel Broadwell, I upgraded my Ubuntu to use the 14.04.2 Hardware Enablement stack (matches 14.10 hardware support): sudo apt install --install-recommends libgles2-mesa-lts-utopic libglapi-mesa-lts-utopic linux-generic-lts-utopic xserver-xorg-lts-utopic libgl1-mesa-dri-lts-utopic libegl1-mesa-drivers-lts-utopic libgl1-mesa-glx-lts-utopic:i386
Even though it's much better than a normal Ubuntu 14.10 would be since many of the Dell fixes continue to be in use, some functionality might become worse compared to the pre-installed stack. The only thing I have noticed though is the internal microphone not working anymore out-of-the-box, requiring a kernel patch as mentioned in Dell's notes. This is not a surprise since the real eventual upstream support involves switching from HDA to I2S and during 14.10 kernel work that was not nearly done. If you're excited about new drivers, I'd recommend waiting until August when the 15.04 based 14.04.3 stack is available (same package names, but 'vivid' instead of 'utopic'). [edit: I couldn't resist myself when I saw linux-generic-lts-vivid (3.19 kernel) is already in the archives. 14.04.2 + that gives me working microphone again!] [edit 08/2015: full 14.04.3 HWE stack now available, improves graphics performance and features among else, everything seems good: sudo apt install --install-recommends linux-generic-lts-vivid libgles2-mesa-lts-vivid libglapi-mesa-lts-vivid xserver-xorg-lts-vivid libgl1-mesa-dri-lts-vivid libegl1-mesa-lts-vivid libgl1-mesa-glx-lts-vivid:i386 libegl1-mesa-lts-vivid libwayland-egl1-mesa-lts-vivid mesa-vdpau-drivers-lts-vivid libgl1-mesa-dri-lts-vivid:i386 ]


Dell XPS 13 Developer Edition with Ubuntu 14.04 LTS is an extremely capable laptop + OS combination nearing perfection, but not quite there because of the software problems in the launch pre-install image. The laptop looks great, feels like a quality product should and is very compact for the screen size.

I've moved over all my work onto it and everything so far is working smoothly in my day-to-day tasks. I'm staying at Ubuntu 14.04 LTS and using my previous LXC configuration to run the latest Ubuntu and Debian development versions. I've also done some interesting changes already like LUKS In-Place Conversion, converting the pre-installed Ubuntu into whole disk encrypted one (not recommended for the faint hearted, GRUB reconfiguration is a bit of a pain).

I look happily forward to working a few productive years with this one!