Affected computers show long delays during boot, especially with applications that need randomness for initialization - including openssh, so it can leave a machine apparently dead after a Stretch-to-Buster upgrade.

If you're sitting in front of a machine that might be suffering from this problem then you may be able to speed up its recovery by jiggling the mouse. If it's a remote system, ping a network interface.

Underlying Problem

Linux is being stricter about getting urandom initialized with properly random randomness, and systemd... well, let's just say it isn't helping. As a result the system has to slowly collect entropy from other sources.


debian-devel thread:,

bug #912087 (bug #912616) bug #916690 bug #923675

Buster release-notes


boot-time delay, crng, hang, getrandom, randomness, systemd