Re: Encrypted containers & the Debian installer.
On Thu 17 May 2018 at 22:24:01 (-0700), Diagonal Arg wrote:
> ---- On Wed, 16 May 2018 07:42:42 -0700 David Wright <firstname.lastname@example.org> wrote ----
> > On Tue 15 May 2018 at 23:05:10 (-0700), Diagonal Arg wrote:
> > > On my first tries with the Debian installer, I am struggling with the limited resources for installing to encrypted disks. I am using the same technique I have used with Ubuntu, but failing at the last step:
> > >
> > > I create my luks disk(s) before-hand, then run the installer. I find I have to anna-install cryptsetup-udeb, as there is no such choice in "Load Installer Modules". Dropping to a shell, opening the disk, and re-detecting hard drives allows me to carry out the installation (as long as there's a filesystem in the mapped device), but on reboot I'm at an initramfs without cryptsetup. So I use a debian-live to pivot into the system to create a crypttab. I find I also have to install cryptsetup. Then I run update-initramfs. Here is where I'm stuck. The new initramfs still does not include cryptsetup. Why is it not recognizing the crypttab?
> > │ [ ] crypto-dm-modules-4.9.0-2-686-di: devicemapper crypto module ▮ │
> David - thanks, but crypto-dm-modules does not include cryptsetup.
> And, even when I anna-install it, it doesn't help with the other issues I mentioned above.
OK, well I haven't got time to check this out but here's my guess of
what's going on. I've never used anna-install to play tricks behind
the installer's back. If you take upon yourself the unlocking of
encrypted disks and then use the d-i to build a system, the d-i may
be unaware that there are any encrypted partitions in the installation.
I can also see from other people's comments elsewhere that you might
be within a hair's breadth of wiping your encrypted partition(s)
during this process. However, just to get the necessary software
installed by the d-i in the final product, a workaround to try
might be to create during installation an encrypted partition on,
say, a nonce stick for a nonce mountpoint.
As I say, I haven't tried it out. Risks are that using the d-i's
partitioner to encrypt the stick does something simultaneously to
the original partitions you're trying to preserve, and also the
/etc/crypttab that gets written will want the stick to be present
at first boot (before you rewrite it).
Sometime I will try this out on a scratch PC. Mine all have room
for two systems, so I can install A, encrypted in the usual manner
and then try installing on the B root partition, keeping the
shared encrypted /home partition. (I haven't used LVM so can't
see how that would interact with things.)