Avoiding low-memory warning in preseed mode

[Fred Boiteux]

    Hello,

When launching the install of a Debian Buster 10.1 on a VM with a small 
memory footprint (512Mb), I get a warning from the Debian installer 
about entering in low-memory mode. I would like to have a 
non-interactive installation using a preseed file, but I didn't found 
how to avoid this warning which blocks installation until I manually 
validates the message in console. I've digged on Internet, and tried 
following preseed paragraph, without success :



d-i lowmem/low note


Does someone can tell me which sentence is supposed to be used in 
preseed file to skip this manual validation ?



    Thanks,

        Fred.

Bug#941300: finish-install: write random seed to correct location for chosen init system

[Paul Wise]

On Tue, 2019-10-01 at 11:55 +0100, Steve McIntyre wrote:

> Wouldn't it just be easier to write it one location and replace the
> other with a symlink to it?

Looks like neither the urandom init script nor systemd-random-seed
unlink the file before writing to it, so this could potentially work
unless that changes at some point. Just writing two different seeds
avoids the need to care about what the implementations will do in the
future so I think it is safer.

Looking at systemd's documentation, on non-virtual systems d-i should
probably also write to the random seed stored in the UEFI ESP, in case
the user decides to use systemd-boot instead of initramfs-tools.

https://systemd.io/RANDOM_SEEDS.html

-- 
bye,
pabs

https://wiki.debian.org/PaulWise


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Bug#941300: finish-install: write random seed to correct location for chosen init system

[Steve McIntyre]

On Sat, Sep 28, 2019 at 05:20:47PM +0800, Paul Wise wrote:
>Package: finish-install
>Version: 2.56
>Severity: important
>Tags: security
>Control: found -1 2.81
>Control: found -1 2.100
>Control: found -1 2.101
>
>finish-install creates a random seed in the location used by the
>urandom init script from the initscripts package. On systemd based
>systems, systemd-random-seed.service overrides the urandom init script
>but uses a different location for its random seed file. Consequently on
>first boot of systemd based systems there is no random seed file so the
>amount of entropy available is lower.
>
>/var/lib/urandom/random-seed
>/var/lib/systemd/random-seed
>
>I think finish-install needs to fix this with one of these options:
>
>   1. Write the random seed to both locations. This means that when
>  switching init systems you get the old random seed.
>   2. Write two different random seeds to the two locations. This means
>  that when switching init systems you get the a new random seed that
>  has never been used before, but which was generated during the
>  install.
>   3. Detect the chosen init system and write the random seed to the
>  location preferred by that init system. This means that when
>  switching init systems the first boot of the new init systems has no
>  random seed.
>
>I think probably the second scenario is the best since then there is
>always a random seed available even when switching init systems and
>that random seed is never reused.

Wouldn't it just be easier to write it one location and replace the
other with a symlink to it?

-- 
Steve McIntyre, Cambridge, UK.st...@einval.com
< sladen> I actually stayed in a hotel and arrived to find a post-it
  note stuck to the mini-bar saying "Paul: This fridge and
  fittings are the correct way around and do not need altering"