Installing with btrfs on LVM on dm-crypt

[Dmitriy Volkov]

Hello,

I'm trying to install Fedora 23 with a following partition layout:

[disk1]
- `/boot`

[disk2]
- cryptdevice
    - LVM
        - btrfs `/` (with btrfs subvolumes, which is irrelevant here)
        - swap

I have to use this relatively complicated layout to be able to 1) use dm-crypt plain mode on disk2 and 2) have proper swap with btrfs; it faired quite well with Arch.

I can't seem to find a proper way to do this: neither anaconda's GUI or (obviously) text mode allow such a setup. Should I write a kickstart file?

Regards,
wldhx

[Corey W Sheldon]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

On 05/01/2016 03:37 PM, Dmitriy Volkov wrote:
> Hello,
>
> I'm trying to install Fedora 23 with a following partition layout:
>
> [disk1] - `/boot`
>
> [disk2] - cryptdevice - LVM - btrfs `/` (with btrfs subvolumes,
> which is irrelevant here) - swap
>
> I have to use this relatively complicated layout to be able to 1)
> use dm-crypt plain mode on disk2 and 2) have proper swap with
> btrfs; it faired quite well with Arch.
>
> I can't seem to find a proper way to do this: neither anaconda's
> GUI or (obviously) text mode allow such a setup. Should I write a
> kickstart file?
>
> Regards, wldhx -- users mailing list [e-mail] 
> To unsubscribe or change subscription options: 
> http://lists.fedoraproject.org/admin/lists/[e-mail].o

rg
>

Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
> Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines 
> Have a question? Ask away: http://ask.fedoraproject.org

Sanest  thing  would be a  kickstart with  desired  layout in  %pre
AND NO #clearpart OR  #Autopart  as that would nullify your efforts

- -- 
- --- Warm Regards ---
Corey Sheldon
P: [phone]
PGP: B54B7228 (keybase) | 5A88E539 (personal) | D2264944 (fedora)
https://gist.github.com/linux-modder/ac5dc6fa211315c633c9

Disclaimer: This document, including attachments, is intended for the
person(s) named within and may contain confidential and/or legally
privileged information, and may occasionally include Intellectual
Property / Embargoed Content. it is request that all emails regardless
of topic or content are regarded in this manner. Unauthorized
disclosure, copying / distribution of this information may be unlawful
and is prohibited, including unsolicited Cc/Bcc. If you are not the
intended recipient, please disregard and destroy this message and if
the recipient is  known to you please inform them, and a return email
indicating a improper recipient IS requested so that I may remove you
from any lists, conversations such error may have created / allowed.
Use of OpenGPG keys are highly encouraged my keys can be found @
hkp://keys.gnupg.net & hkp://keys.fedoraproject.org
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v2
>
> iF4EARYIAAYFAlcnuGQACgkQrio19Q2QBZCu2gD+JHAyE+o2k+yLb3tTqv+aMzsx
> UzWppvW6U9BKBkTjIyYBAJP5zRbadJbVb17MpTUeZOem1TbgLCPWYs6dfvJQVVUM
> =KiM/
> -----END PGP SIGNATURE-----

[Chris Murphy]

On Sun, May 1, 2016 at 1:37 PM, Dmitriy Volkov  wrote:
> Hello,
>
> I'm trying to install Fedora 23 with a following partition layout:
>
> [disk1]
> `/boot`
>
> [disk2]
> cryptdevice
> LVM
> btrfs `/` (with btrfs subvolumes, which is irrelevant here)
> swap

The installer GUI definitely doesn't let you create this layout. I'm
not sure if kickstart will, you should ask on the Anaconda list. It
may not either because LVM is a kind of device and so is Btrfs, and
device types, I *think* are all mutually exclusive and can't be
stacked/nested.
> I have to use this relatively complicated layout to be able to 1) use dm-crypt plain mode on disk2 and 2) have proper swap with btrfs; it faired quite well with Arch.

Well the installer doesn't create plain crypt devices either, so no
matter what you're doing something outside the installer, so what
ought to be true is if you create the layout in advance, the installer
will let you use it.

Trick 1 is to make sure all usable space is partitioned somehow (leave
no unallocated space). If there's allocated space the installer will
try to use it and create a new Btrfs volume. So make a boot partition
on disk 1 (format it, don't format it, doesn't matter), and then make
another partition for the rest of the space, the type code doesn't
matter.

Trick 2 is in the installer's custom/manual partitioning, first choose
Btrfs in the partition scheme pop-up menu, then:

Click on Unknown to reveal precreated items, click on precreated boot,
assign mount point /boot, check format, click apply
Click again on unknown, click precreated swap, choose swap as fs,
maybe you have to check format, click apply
Click +  and choose mount point / without a size. This creates root
subvolume on existing Btrfs.
Click + and choose mount point /home without size. This creates home
subvolume on existing Btrfs.

Crap. I just thought of something. I don't know whether anaconda will
let you install to plain crypt at all because it doesn't offer a UI to
unlock what it doesn't recognize. And it only recognizes LUKS. Maybe
if it's already unlocked, and LVM is active, maybe it's possible.

[Tim]

Allegedly, on or about 02 May 2016, Chris Murphy sent:
> Crap. I just thought of something. I don't know whether anaconda will
> let you install to plain crypt at all because it doesn't offer a UI to
> unlock what it doesn't recognize. And it only recognizes LUKS. Maybe
> if it's already unlocked, and LVM is active, maybe it's possible.

My trick for custom partitioning, a long time ago, was to wait for the
install routine to pause at some point before partitioning questions
occurred, CTRL+ALT+Fn to another console, and run fdisk to set up what I
wanted, then CTRL+ALT+F1 (or whatever it was) to get back to the
installer.

I wonder if it's possible to do something similar, still?  With the
added thing you mention of mounting your partitions before going back to
the installer.

[Samuel Sieb]

On 05/02/2016 10:50 PM, Tim wrote:
> My trick for custom partitioning, a long time ago, was to wait for the
> install routine to pause at some point before partitioning questions
> occurred, CTRL+ALT+Fn to another console, and run fdisk to set up what I
> wanted, then CTRL+ALT+F1 (or whatever it was) to get back to the
> installer.
>
> I wonder if it's possible to do something similar, still?  With the
> added thing you mention of mounting your partitions before going back to
> the installer.

Should be possible.  Do CTRL-ALT-F1 to get to the console, then ALT-TAB 
to get to the shell prompt.  You can do all the disk management you want 
(at least with the limited utilities in the installer image).  Switch 
back to the installer with (at least in F23) ALT-F6.  Go to the disk 
spoke and get it to rescan the disks.

[Dmitriy Volkov]

Thanks for the idea - switching to alternate vconsoles does work. Vconsole 1 also has tmux with various logs open - handy.

[Dmitriy Volkov]

So, I'm now trying to make the installer discover my partitions. Apparently, won't be as easy as just creating and maybe mounting them.

Currently, my LVs do get discovered by blivet, but it then tries to get their corresponding VG, which naturally depends on PV, for which it needs the cryptdevice, which it ignores - I'm pretty sure I'm hitting this [0] codepath.

[0] - https://github.com/rhinstaller/blivet/blob/70ae22c50b8bec1a88054a4b521a1b7c0...