The default behavior of a stock Ubuntu LTS server install is that it enables 'unattended upgrades', by installing the package unattended-upgrades (which creates /etc/apt/apt.conf.d/20auto-upgrades, which controls this). Historically, we haven't believed in unattended automatic package upgrades and eventually built a complex semi-automated upgrades system (which has various special features ). In theory this has various potential advantages; in practice it mostly results in package upgrades being applied after some delay that depends on when they come out relative to working days.

I have a few machines that actually are stock Ubuntu servers, for reasons outside the scope of this entry. These machines naturally have automated upgrades turned on and one of them (in a cloud, using the cloud provider's standard Ubuntu LTS image) even appears to automatically reboot itself if kernel updates need that. These machines are all in undemanding roles (although one of them is my work IPv6 gateway ), so they aren't necessarily indicative of what we'd see on more complex machines, but none of them have had any visible problems from these unattended upgrades.

(I also can't remember the last time that we ran into a problem with updates when we applied them. Ubuntu updates still sometimes have regressions and other problems, forcing them to be reverted or reissued, but so far we haven't seen problems ourselves; we find out about these problems only through the notices in the Ubuntu security lists.)

If we were starting from scratch today in a greenfield environment, I'm not sure we'd bother building our automation for manual package updates. Since we have the automation and it offers various extra features (even if they're rarely used), we're probably not going to switch over to automated upgrades (including in our local build of Ubuntu 26.04 LTS when that comes out next year).

(The advantage of switching over to standard unattended upgrades is that we'd get rid of a local tool that, like all local tools, is all our responsibility. The less local weird things we have, the better, especially since we have so many as it is.)