Trixie uses more RAM → breaks some common usage scenarios

Why?

There are multiple potential reasons.

What we already know:

  • the initramfs grew a lot, and we lock it into memory (thanks to newly supported graphics cards, so new firmware included in the initrd: #21006 (comment 265138))

General solutions

The only way to fix this is to:

Mitigations for specific problems

We probably haven't identified all the use cases that are now broken. So below we're only talking about issues we're already aware of.

Additional Software

While working on #21010 (closed), anonym saw Scenario: I set up Additional Software when installing a package without persistent partition and the package is installed next time I start Tails fail with "Not enough memory to create Persistent Storage".

We can cheaply fix this particular instance of the problem by decreasing MINIMUM_PBKDF_MEMORY_KIB, which we currently set to 256 MiB, under the assumption that "even when the system doesn't have enough available memory, the user can free up some memory by closing applications and try again", which is not really the case when the memory is being used by the APT cache & lists, plus the dpkg database, plus the Additional Package that one just installed and which use RAM in the tmpfs branch of our overlayfs root directory.

The consequence is that:

  • slightly decreased security in some cases, but cryptsetup sometimes uses as little as 32 KiB, so this should still be plenty enough
  • more systems will need to go through the upgrade process in the Welcome Screen
Edited by intrigeri